31920040661 has 8 divisors (see below), whose sum is σ = 33715993344. Its totient is φ = 30171980160.

The previous prime is 31920040651. The next prime is 31920040673. The reversal of 31920040661 is 16604002913.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31920040661 - 2¹⁰ = 31920039637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31920040651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11971676 + ... + 11974341.

It is an arithmetic number, because the mean of its divisors is an integer number (4214499168).

Almost surely, 2^31920040661 is an apocalyptic number.

31920040661 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

31920040661 is a deficient number, since it is larger than the sum of its proper divisors (1795952683).

31920040661 is a wasteful number, since it uses less digits than its factorization.

31920040661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23946091.

The product of its (nonzero) digits is 7776, while the sum is 32.

The spelling of 31920040661 in words is "thirty-one billion, nine hundred twenty million, forty thousand, six hundred sixty-one".