21612520447579 has 2 divisors, whose sum is σ = 21612520447580. Its totient is φ = 21612520447578.

The previous prime is 21612520447489. The next prime is 21612520447601. The reversal of 21612520447579 is 97574402521612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21612520447579 - 2³⁷ = 21475081494107 is a prime.

It is a super-2 number, since 2×21612520447579² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21612520447079) 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 as a sum of consecutive naturals, namely, 10806260223789 + 10806260223790.

It is an arithmetic number, because the mean of its divisors is an integer number (10806260223790).

Almost surely, 2^{21612520447579} is an apocalyptic number.

21612520447579 is a deficient number, since it is larger than the sum of its proper divisors (1).

21612520447579 is an equidigital number, since it uses as much as digits as its factorization.

21612520447579 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8467200, while the sum is 55.

The spelling of 21612520447579 in words is "twenty-one trillion, six hundred twelve billion, five hundred twenty million, four hundred forty-seven thousand, five hundred seventy-nine".