20931181590 has 64 divisors (see below), whose sum is σ = 54845268480. Its totient is φ = 5070186240.

The previous prime is 20931181589. The next prime is 20931181637. The reversal of 20931181590 is 9518113902.

It is a super-2 number, since 2×20931181590² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 400767 + ... + 449973.

It is an arithmetic number, because the mean of its divisors is an integer number (856957320).

Almost surely, 2^20931181590 is an apocalyptic number.

20931181590 is an abundant number, since it is smaller than the sum of its proper divisors (33914086890).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20931181590 is a wasteful number, since it uses less digits than its factorization.

20931181590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50517.

The product of its (nonzero) digits is 19440, while the sum is 39.

The spelling of 20931181590 in words is "twenty billion, nine hundred thirty-one million, one hundred eighty-one thousand, five hundred ninety".