21474931780 has 12 divisors (see below), whose sum is σ = 45097356780. Its totient is φ = 8589972704.

The previous prime is 21474931771. The next prime is 21474931783. The reversal of 21474931780 is 8713947412.

It can be written as a sum of positive squares in 2 ways, for example, as 3364232004 + 18110699776 = 58002^2 + 134576^2 .

It is a super-2 number, since 2×21474931780² (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 21474931780.

It is not an unprimeable number, because it can be changed into a prime (21474931783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 536873275 + ... + 536873314.

It is an arithmetic number, because the mean of its divisors is an integer number (3758113065).

Almost surely, 2^21474931780 is an apocalyptic number.

21474931780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21474931780 is an abundant number, since it is smaller than the sum of its proper divisors (23622425000).

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

21474931780 is a wasteful number, since it uses less digits than its factorization.

21474931780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073746598 (or 1073746596 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 46.

The spelling of 21474931780 in words is "twenty-one billion, four hundred seventy-four million, nine hundred thirty-one thousand, seven hundred eighty".