20858732778 has 32 divisors (see below), whose sum is σ = 44932700736. Its totient is φ = 6417186048.

The previous prime is 20858732761. The next prime is 20858732809. The reversal of 20858732778 is 87723785802.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 759250 + ... + 786242.

It is an arithmetic number, because the mean of its divisors is an integer number (1404146898).

Almost surely, 2^20858732778 is an apocalyptic number.

20858732778 is an abundant number, since it is smaller than the sum of its proper divisors (24073967958).

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

20858732778 is a wasteful number, since it uses less digits than its factorization.

20858732778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36918.

The product of its (nonzero) digits is 10536960, while the sum is 57.

The spelling of 20858732778 in words is "twenty billion, eight hundred fifty-eight million, seven hundred thirty-two thousand, seven hundred seventy-eight".