31955627981 has 4 divisors (see below), whose sum is σ = 32558564412. Its totient is φ = 31352691552.

The previous prime is 31955627969. The next prime is 31955627987. The reversal of 31955627981 is 18972655913.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28311091081 + 3644536900 = 168259^2 + 60370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31955627981 is a prime.

It is a super-2 number, since 2×31955627981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31955627987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301468136 + ... + 301468241.

It is an arithmetic number, because the mean of its divisors is an integer number (8139641103).

Almost surely, 2^31955627981 is an apocalyptic number.

It is an amenable number.

31955627981 is a deficient number, since it is larger than the sum of its proper divisors (602936431).

31955627981 is an equidigital number, since it uses as much as digits as its factorization.

31955627981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602936430.

The product of its digits is 4082400, while the sum is 56.

The spelling of 31955627981 in words is "thirty-one billion, nine hundred fifty-five million, six hundred twenty-seven thousand, nine hundred eighty-one".