20831731280 has 40 divisors (see below), whose sum is σ = 48479281800. Its totient is φ = 8324863488.

The previous prime is 20831731267. The next prime is 20831731307. The reversal of 20831731280 is 8213713802.

It can be written as a sum of positive squares in 4 ways, for example, as 24245776 + 20807485504 = 4924^2 + 144248^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×20831731280² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20831731280.

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 7 ways as a sum of consecutive naturals, for example, 36275 + ... + 207314.

It is an arithmetic number, because the mean of its divisors is an integer number (1211982045).

Almost surely, 2^20831731280 is an apocalyptic number.

20831731280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20831731280 is an abundant number, since it is smaller than the sum of its proper divisors (27647550520).

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

20831731280 is a wasteful number, since it uses less digits than its factorization.

20831731280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244671 (or 244665 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The spelling of 20831731280 in words is "twenty billion, eight hundred thirty-one million, seven hundred thirty-one thousand, two hundred eighty".