21712106660 has 24 divisors (see below), whose sum is σ = 45726084600. Its totient is φ = 8659954944.

The previous prime is 21712106621. The next prime is 21712106671. The reversal of 21712106660 is 6660121712.

It can be written as a sum of positive squares in 4 ways, for example, as 3986912164 + 17725194496 = 63142^2 + 133136^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1548329 + ... + 1562288.

It is an arithmetic number, because the mean of its divisors is an integer number (1905253525).

Almost surely, 2^21712106660 is an apocalyptic number.

21712106660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21712106660 is an abundant number, since it is smaller than the sum of its proper divisors (24013977940).

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

21712106660 is a wasteful number, since it uses less digits than its factorization.

21712106660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3110975 (or 3110973 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The spelling of 21712106660 in words is "twenty-one billion, seven hundred twelve million, one hundred six thousand, six hundred sixty".