20666362564 has 9 divisors (see below), whose sum is σ = 36166637647. Its totient is φ = 10333037524.

The previous prime is 20666362537. The next prime is 20666362571. The reversal of 20666362564 is 46526366602.

The square root of 20666362564 is 143758.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 251577 + ... + 323455.

Almost surely, 2^20666362564 is an apocalyptic number.

20666362564 is the 143758-th square number.

It is an amenable number.

20666362564 is a deficient number, since it is larger than the sum of its proper divisors (15500275083).

20666362564 is an frugal number, since it uses more digits than its factorization.

20666362564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143762 (or 71881 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 46.

The spelling of 20666362564 in words is "twenty billion, six hundred sixty-six million, three hundred sixty-two thousand, five hundred sixty-four".