21656086670573 has 2 divisors, whose sum is σ = 21656086670574. Its totient is φ = 21656086670572.

The previous prime is 21656086670507. The next prime is 21656086670627. The reversal of 21656086670573 is 37507668065612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20031550338244 + 1624536332329 = 4475662^2 + 1274573^2 .

It is a cyclic number.

It is not a de Polignac number, because 21656086670573 - 2¹⁰ = 21656086669549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21656086670173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10828043335286 + 10828043335287.

It is an arithmetic number, because the mean of its divisors is an integer number (10828043335287).

Almost surely, 2^{21656086670573} is an apocalyptic number.

It is an amenable number.

21656086670573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21656086670573 is an equidigital number, since it uses as much as digits as its factorization.

21656086670573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 76204800, while the sum is 62.

The spelling of 21656086670573 in words is "twenty-one trillion, six hundred fifty-six billion, eighty-six million, six hundred seventy thousand, five hundred seventy-three".