21612375461 has 2 divisors, whose sum is σ = 21612375462. Its totient is φ = 21612375460.

The previous prime is 21612375443. The next prime is 21612375479. The reversal of 21612375461 is 16457321612.

It is a balanced prime because it is at equal distance from previous prime (21612375443) and next prime (21612375479).

It can be written as a sum of positive squares in only one way, i.e., 13263898561 + 8348476900 = 115169^2 + 91370^2 .

It is a cyclic number.

It is not a de Polignac number, because 21612375461 - 2²² = 21608181157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21612375061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10806187730 + 10806187731.

It is an arithmetic number, because the mean of its divisors is an integer number (10806187731).

Almost surely, 2^21612375461 is an apocalyptic number.

It is an amenable number.

21612375461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21612375461 is an equidigital number, since it uses as much as digits as its factorization.

21612375461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 38.

The spelling of 21612375461 in words is "twenty-one billion, six hundred twelve million, three hundred seventy-five thousand, four hundred sixty-one".