21157055052 has 48 divisors (see below), whose sum is σ = 56442473472. Its totient is φ = 6042337920.

The previous prime is 21157054979. The next prime is 21157055081. The reversal of 21157055052 is 25055075112.

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, 153453 + ... + 256635.

It is an arithmetic number, because the mean of its divisors is an integer number (1175884864).

Almost surely, 2^21157055052 is an apocalyptic number.

It is an amenable number.

21157055052 is an abundant number, since it is smaller than the sum of its proper divisors (35285418420).

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

21157055052 is a wasteful number, since it uses less digits than its factorization.

21157055052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105638 (or 105636 counting only the distinct ones).

The product of its (nonzero) digits is 17500, while the sum is 33.

The spelling of 21157055052 in words is "twenty-one billion, one hundred fifty-seven million, fifty-five thousand, fifty-two".