20878556 has 6 divisors (see below), whose sum is σ = 36537480. Its totient is φ = 10439276.

The previous prime is 20878541. The next prime is 20878577. The reversal of 20878556 is 65587802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2609816 + ... + 2609823.

It is an arithmetic number, because the mean of its divisors is an integer number (6089580).

Almost surely, 2^20878556 is an apocalyptic number.

It is an amenable number.

20878556 is a deficient number, since it is larger than the sum of its proper divisors (15658924).

20878556 is a wasteful number, since it uses less digits than its factorization.

20878556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5219643 (or 5219641 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 41.

The square root of 20878556 is about 4569.3058553789. The cubic root of 20878556 is about 275.3595561301.

The spelling of 20878556 in words is "twenty million, eight hundred seventy-eight thousand, five hundred fifty-six".