21388524658 has 32 divisors (see below), whose sum is σ = 33113808000. Its totient is φ = 10353619584.

The previous prime is 21388524649. The next prime is 21388524667. The reversal of 21388524658 is 85642588312.

It is an interprime number because it is at equal distance from previous prime (21388524649) and next prime (21388524667).

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, 20388918 + ... + 20389966.

It is an arithmetic number, because the mean of its divisors is an integer number (1034806500).

Almost surely, 2^21388524658 is an apocalyptic number.

21388524658 is a deficient number, since it is larger than the sum of its proper divisors (11725283342).

21388524658 is a wasteful number, since it uses less digits than its factorization.

21388524658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2194.

The product of its digits is 3686400, while the sum is 52.

The spelling of 21388524658 in words is "twenty-one billion, three hundred eighty-eight million, five hundred twenty-four thousand, six hundred fifty-eight".