1251121331331 has 12 divisors (see below), whose sum is σ = 1807192140208. Its totient is φ = 834073095024.

The previous prime is 1251121331321. The next prime is 1251121331351. The reversal of 1251121331331 is 1331331211521.

1251121331331 is a `hidden beast` number, since 1 + 2 + 511 + 2 + 13 + 3 + 133 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-1251121331331 is a prime.

It is a super-2 number, since 2×1251121331331² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1251121331295 and 1251121331304.

It is not an unprimeable number, because it can be changed into a prime (1251121331311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 468801 + ... + 1649853.

Almost surely, 2^{1251121331331} is an apocalyptic number.

1251121331331 is a deficient number, since it is larger than the sum of its proper divisors (556070808877).

1251121331331 is a wasteful number, since it uses less digits than its factorization.

1251121331331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1298762 (or 1298759 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

Adding to 1251121331331 its reverse (1331331211521), we get a palindrome (2582452542852).

The spelling of 1251121331331 in words is "one trillion, two hundred fifty-one billion, one hundred twenty-one million, three hundred thirty-one thousand, three hundred thirty-one".