21657156054 has 16 divisors (see below), whose sum is σ = 44484969648. Its totient is φ = 7023942432.

The previous prime is 21657156041. The next prime is 21657156067. The reversal of 21657156054 is 45065175612.

It is an interprime number because it is at equal distance from previous prime (21657156041) and next prime (21657156067).

It is a junction number, because it is equal to n+sod(n) for n = 21657155997 and 21657156015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48777157 + ... + 48777600.

It is an arithmetic number, because the mean of its divisors is an integer number (2780310603).

Almost surely, 2^21657156054 is an apocalyptic number.

21657156054 is an abundant number, since it is smaller than the sum of its proper divisors (22827813594).

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

21657156054 is a wasteful number, since it uses less digits than its factorization.

21657156054 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97554799.

The product of its (nonzero) digits is 252000, while the sum is 42.

The spelling of 21657156054 in words is "twenty-one billion, six hundred fifty-seven million, one hundred fifty-six thousand, fifty-four".