31917021653 has 4 divisors (see below), whose sum is σ = 34818569088. Its totient is φ = 29015474220.

The previous prime is 31917021611. The next prime is 31917021701. The reversal of 31917021653 is 35612071913.

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 not a de Polignac number, because 31917021653 - 2⁶ = 31917021589 is a prime.

It is a super-4 number, since 4×31917021653⁴ (a number of 43 digits) contains 4444 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 (31917021853) 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, 1450773701 + ... + 1450773722.

It is an arithmetic number, because the mean of its divisors is an integer number (8704642272).

Almost surely, 2^31917021653 is an apocalyptic number.

It is an amenable number.

31917021653 is a deficient number, since it is larger than the sum of its proper divisors (2901547435).

31917021653 is a wasteful number, since it uses less digits than its factorization.

31917021653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2901547434.

The product of its (nonzero) digits is 34020, while the sum is 38.

The spelling of 31917021653 in words is "thirty-one billion, nine hundred seventeen million, twenty-one thousand, six hundred fifty-three".