20987168 has 12 divisors (see below), whose sum is σ = 41318550. Its totient is φ = 10493568.

The previous prime is 20987159. The next prime is 20987171. The reversal of 20987168 is 86178902.

It can be written as a sum of positive squares in only one way, i.e., 19963024 + 1024144 = 4468^2 + 1012^2 .

It is a super-2 number, since 2×20987168² = 880922441320448, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327893 + ... + 327956.

Almost surely, 2^20987168 is an apocalyptic number.

It is an amenable number.

20987168 is a deficient number, since it is larger than the sum of its proper divisors (20331382).

20987168 is an equidigital number, since it uses as much as digits as its factorization.

20987168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 655859 (or 655851 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20987168 is about 4581.1753950269. The cubic root of 20987168 is about 275.8362117201.

The spelling of 20987168 in words is "twenty million, nine hundred eighty-seven thousand, one hundred sixty-eight".