31680173821 has 8 divisors (see below), whose sum is σ = 32706895104. Its totient is φ = 30653751360.

The previous prime is 31680173783. The next prime is 31680173831. The reversal of 31680173821 is 12837108613.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31680173821 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 (31680173831) 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, 151701 + ... + 293893.

It is an arithmetic number, because the mean of its divisors is an integer number (4088361888).

Almost surely, 2^31680173821 is an apocalyptic number.

31680173821 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

31680173821 is a deficient number, since it is larger than the sum of its proper divisors (1026721283).

31680173821 is a wasteful number, since it uses less digits than its factorization.

31680173821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149411.

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 31680173821 in words is "thirty-one billion, six hundred eighty million, one hundred seventy-three thousand, eight hundred twenty-one".