20977638 has 32 divisors (see below), whose sum is σ = 47250432. Its totient is φ = 6151200.

The previous prime is 20977613. The next prime is 20977657. The reversal of 20977638 is 83677902.

It is a super-2 number, since 2×20977638² = 880122592118088, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20977638.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 3081 + ... + 7172.

It is an arithmetic number, because the mean of its divisors is an integer number (1476576).

Almost surely, 2^20977638 is an apocalyptic number.

20977638 is an abundant number, since it is smaller than the sum of its proper divisors (26272794).

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

20977638 is a wasteful number, since it uses less digits than its factorization.

20977638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10300.

The product of its (nonzero) digits is 127008, while the sum is 42.

The square root of 20977638 is about 4580.1351508444. The cubic root of 20977638 is about 275.7944541870.

The spelling of 20977638 in words is "twenty million, nine hundred seventy-seven thousand, six hundred thirty-eight".