1211251120 has 80 divisors (see below), whose sum is σ = 2962980000. Its totient is φ = 459812864.

The previous prime is 1211251117. The next prime is 1211251123. The reversal of 1211251120 is 211521121.

It is an interprime number because it is at equal distance from previous prime (1211251117) and next prime (1211251123).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 1211251094 and 1211251103.

It is not an unprimeable number, because it can be changed into a prime (1211251123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 132456 + ... + 141304.

It is an arithmetic number, because the mean of its divisors is an integer number (37037250).

Almost surely, 2^1211251120 is an apocalyptic number.

1211251120 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 1211251120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1481490000).

1211251120 is an abundant number, since it is smaller than the sum of its proper divisors (1751728880).

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

1211251120 is a wasteful number, since it uses less digits than its factorization.

1211251120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8950 (or 8944 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 16.

The square root of 1211251120 is about 34803.0332011450. The cubic root of 1211251120 is about 1065.9693819548.

Adding to 1211251120 its reverse (211521121), we get a palindrome (1422772241).

The spelling of 1211251120 in words is "one billion, two hundred eleven million, two hundred fifty-one thousand, one hundred twenty".