21523033979 has 2 divisors, whose sum is σ = 21523033980. Its totient is φ = 21523033978.

The previous prime is 21523033963. The next prime is 21523034011. The reversal of 21523033979 is 97933032512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21523033979 - 2⁴ = 21523033963 is a prime.

It is a super-2 number, since 2×21523033979² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21523033949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10761516989 + 10761516990.

It is an arithmetic number, because the mean of its divisors is an integer number (10761516990).

Almost surely, 2^21523033979 is an apocalyptic number.

21523033979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21523033979 is an equidigital number, since it uses as much as digits as its factorization.

21523033979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 306180, while the sum is 44.

The spelling of 21523033979 in words is "twenty-one billion, five hundred twenty-three million, thirty-three thousand, nine hundred seventy-nine".