31951153961 has 4 divisors (see below), whose sum is σ = 33340334592. Its totient is φ = 30561973332.

The previous prime is 31951153921. The next prime is 31951153967. The reversal of 31951153961 is 16935115913.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31951153961 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31951153967) 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, 694590281 + ... + 694590326.

It is an arithmetic number, because the mean of its divisors is an integer number (8335083648).

Almost surely, 2^31951153961 is an apocalyptic number.

It is an amenable number.

31951153961 is a deficient number, since it is larger than the sum of its proper divisors (1389180631).

31951153961 is a wasteful number, since it uses less digits than its factorization.

31951153961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389180630.

The product of its digits is 109350, while the sum is 44.

The spelling of 31951153961 in words is "thirty-one billion, nine hundred fifty-one million, one hundred fifty-three thousand, nine hundred sixty-one".