20957049978 has 64 divisors (see below), whose sum is σ = 44416512000. Its totient is φ = 6578337920.

The previous prime is 20957049977. The next prime is 20957050003. The reversal of 20957049978 is 87994075902.

It is not an unprimeable number, because it can be changed into a prime (20957049977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10277083 + ... + 10279121.

It is an arithmetic number, because the mean of its divisors is an integer number (694008000).

Almost surely, 2^20957049978 is an apocalyptic number.

20957049978 is an abundant number, since it is smaller than the sum of its proper divisors (23459462022).

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

20957049978 is a wasteful number, since it uses less digits than its factorization.

20957049978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3187.

The product of its (nonzero) digits is 11430720, while the sum is 60.

The spelling of 20957049978 in words is "twenty billion, nine hundred fifty-seven million, forty-nine thousand, nine hundred seventy-eight".