20897880 has 32 divisors (see below), whose sum is σ = 62694000. Its totient is φ = 5572736.

The previous prime is 20897873. The next prime is 20897909. The reversal of 20897880 is 8879802.

It is a happy number.

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, 86955 + ... + 87194.

Almost surely, 2^20897880 is an apocalyptic number.

20897880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20897880 is an abundant number, since it is smaller than the sum of its proper divisors (41796120).

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

20897880 is a wasteful number, since it uses less digits than its factorization.

20897880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174163 (or 174159 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 20897880 is about 4571.4199107061. The cubic root of 20897880 is about 275.4444822985. Note that the first 4 decimals are identical.

The spelling of 20897880 in words is "twenty million, eight hundred ninety-seven thousand, eight hundred eighty".