1211000120 has 128 divisors (see below), whose sum is σ = 3135283200. Its totient is φ = 416870400.

The previous prime is 1211000081. The next prime is 1211000159. The reversal of 1211000120 is 210001121.

1211000120 = 5053² + 5054² + ... + 5099².

It is an interprime number because it is at equal distance from previous prime (1211000081) and next prime (1211000159).

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a junction number, because it is equal to n+sod(n) for n = 1211000098 and 1211000107.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 640136 + ... + 642024.

It is an arithmetic number, because the mean of its divisors is an integer number (24494400).

Almost surely, 2^1211000120 is an apocalyptic number.

1211000120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211000120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1567641600).

1211000120 is an abundant number, since it is smaller than the sum of its proper divisors (1924283080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1211000120 is a wasteful number, since it uses less digits than its factorization.

1211000120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1989 (or 1985 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 1211000120 is about 34799.4270067770. The cubic root of 1211000120 is about 1065.8957454771.

Adding to 1211000120 its reverse (210001121), we get a palindrome (1421001241).

The spelling of 1211000120 in words is "one billion, two hundred eleven million, one hundred twenty", and thus it is an aban number.