31817305990 has 16 divisors (see below), whose sum is σ = 59761201248. Its totient is φ = 12173577856.

The previous prime is 31817305957. The next prime is 31817305991. The reversal of 31817305990 is 9950371813.

It is a happy number.

It is a super-2 number, since 2×31817305990² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a self number, because there is not a number n which added to its sum of digits gives 31817305990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31817305991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69167827 + ... + 69168286.

It is an arithmetic number, because the mean of its divisors is an integer number (3735075078).

Almost surely, 2^31817305990 is an apocalyptic number.

31817305990 is a deficient number, since it is larger than the sum of its proper divisors (27943895258).

31817305990 is a wasteful number, since it uses less digits than its factorization.

31817305990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138336143.

The product of its (nonzero) digits is 204120, while the sum is 46.

The spelling of 31817305990 in words is "thirty-one billion, eight hundred seventeen million, three hundred five thousand, nine hundred ninety".