21612493596961 has 2 divisors, whose sum is σ = 21612493596962. Its totient is φ = 21612493596960.

The previous prime is 21612493596931. The next prime is 21612493596977. The reversal of 21612493596961 is 16969539421612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21106857408400 + 505636188561 = 4594220^2 + 711081^2 .

It is a cyclic number.

It is not a de Polignac number, because 21612493596961 - 2¹⁷ = 21612493465889 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21612493596893 and 21612493596902.

It is not a weakly prime, because it can be changed into another prime (21612493596931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10806246798480 + 10806246798481.

It is an arithmetic number, because the mean of its divisors is an integer number (10806246798481).

Almost surely, 2^{21612493596961} is an apocalyptic number.

It is an amenable number.

21612493596961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21612493596961 is an equidigital number, since it uses as much as digits as its factorization.

21612493596961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37791360, while the sum is 64.

The spelling of 21612493596961 in words is "twenty-one trillion, six hundred twelve billion, four hundred ninety-three million, five hundred ninety-six thousand, nine hundred sixty-one".