21457157579 has 16 divisors (see below), whose sum is σ = 25239029760. Its totient is φ = 17984134560.

The previous prime is 21457157567. The next prime is 21457157591. The reversal of 21457157579 is 97575175412.

It is an interprime number because it is at equal distance from previous prime (21457157567) and next prime (21457157591).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21457157579 is a prime.

It is a super-2 number, since 2×21457157579² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21457157579.

It is not an unprimeable number, because it can be changed into a prime (21457157599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27542 + ... + 208980.

It is an arithmetic number, because the mean of its divisors is an integer number (1577439360).

Almost surely, 2^21457157579 is an apocalyptic number.

21457157579 is a deficient number, since it is larger than the sum of its proper divisors (3781872181).

21457157579 is a wasteful number, since it uses less digits than its factorization.

21457157579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182290.

The product of its digits is 3087000, while the sum is 53.

The spelling of 21457157579 in words is "twenty-one billion, four hundred fifty-seven million, one hundred fifty-seven thousand, five hundred seventy-nine".