1211002120 has 64 divisors (see below), whose sum is σ = 2816130240. Its totient is φ = 468384000.

The previous prime is 1211002043. The next prime is 1211002159. The reversal of 1211002120 is 212001121.

It is a super-2 number, since 2×1211002120² = 2933052269288988800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 1211002097 and 1211002106.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 170235 + ... + 177205.

It is an arithmetic number, because the mean of its divisors is an integer number (44002035).

Almost surely, 2^1211002120 is an apocalyptic number.

1211002120 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 1211002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1408065120).

1211002120 is an abundant number, since it is smaller than the sum of its proper divisors (1605128120).

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

1211002120 is a wasteful number, since it uses less digits than its factorization.

1211002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7126 (or 7122 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1211002120 is about 34799.4557428705. The cubic root of 1211002120 is about 1065.8963322621.

Adding to 1211002120 its reverse (212001121), we get a palindrome (1423003241).

Subtracting from 1211002120 its reverse (212001121), we obtain a palindrome (999000999).

The spelling of 1211002120 in words is "one billion, two hundred eleven million, two thousand, one hundred twenty".