20897660 has 24 divisors (see below), whose sum is σ = 50154720. Its totient is φ = 7164864.

The previous prime is 20897609. The next prime is 20897671. The reversal of 20897660 is 6679802.

It is a congruent number.

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, 74495 + ... + 74774.

It is an arithmetic number, because the mean of its divisors is an integer number (2089780).

Almost surely, 2^20897660 is an apocalyptic number.

20897660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20897660 is an abundant number, since it is smaller than the sum of its proper divisors (29257060).

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

20897660 is a wasteful number, since it uses less digits than its factorization.

20897660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149285 (or 149283 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 20897660 is about 4571.3958480972. The cubic root of 20897660 is about 275.4435157252.

The spelling of 20897660 in words is "twenty million, eight hundred ninety-seven thousand, six hundred sixty".