21275471680 has 28 divisors (see below), whose sum is σ = 50662217700. Its totient is φ = 8510188544.

The previous prime is 21275471599. The next prime is 21275471681. The reversal of 21275471680 is 8617457212.

It can be written as a sum of positive squares in 2 ways, for example, as 9371788864 + 11903682816 = 96808^2 + 109104^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21275471681) 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, 33242605 + ... + 33243244.

Almost surely, 2^21275471680 is an apocalyptic number.

21275471680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21275471680 is an abundant number, since it is smaller than the sum of its proper divisors (29386746020).

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

21275471680 is an equidigital number, since it uses as much as digits as its factorization.

21275471680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66485866 (or 66485856 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 43.

The spelling of 21275471680 in words is "twenty-one billion, two hundred seventy-five million, four hundred seventy-one thousand, six hundred eighty".