20646988 has 12 divisors (see below), whose sum is σ = 36671992. Its totient is φ = 10169280.

The previous prime is 20646973. The next prime is 20647001. The reversal of 20646988 is 88964602.

It is a happy number.

It is a super-2 number, since 2×20646988² = 852596226944288, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38253 + ... + 38788.

Almost surely, 2^20646988 is an apocalyptic number.

It is an amenable number.

20646988 is a deficient number, since it is larger than the sum of its proper divisors (16025004).

20646988 is a wasteful number, since it uses less digits than its factorization.

20646988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77112 (or 77110 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 43.

The square root of 20646988 is about 4543.8956854224. The cubic root of 20646988 is about 274.3377474966.

The spelling of 20646988 in words is "twenty million, six hundred forty-six thousand, nine hundred eighty-eight".