20656157788 has 54 divisors (see below), whose sum is σ = 41818846776. Its totient is φ = 8745407424.

The previous prime is 20656157783. The next prime is 20656157803. The reversal of 20656157788 is 88775165602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20656157783) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 119399670 + ... + 119399842.

Almost surely, 2^20656157788 is an apocalyptic number.

20656157788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20656157788 is an abundant number, since it is smaller than the sum of its proper divisors (21162688988).

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

20656157788 is an equidigital number, since it uses as much as digits as its factorization.

20656157788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 5644800, while the sum is 55.

The spelling of 20656157788 in words is "twenty billion, six hundred fifty-six million, one hundred fifty-seven thousand, seven hundred eighty-eight".