21629642731673 has 2 divisors, whose sum is σ = 21629642731674. Its totient is φ = 21629642731672.

The previous prime is 21629642731633. The next prime is 21629642731727. The reversal of 21629642731673 is 37613724692612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18635901892624 + 2993740839049 = 4316932^2 + 1730243^2 .

It is a cyclic number.

It is not a de Polignac number, because 21629642731673 - 2³⁰ = 21628568989849 is a prime.

It is not a weakly prime, because it can be changed into another prime (21629642731603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10814821365836 + 10814821365837.

It is an arithmetic number, because the mean of its divisors is an integer number (10814821365837).

Almost surely, 2^{21629642731673} is an apocalyptic number.

It is an amenable number.

21629642731673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21629642731673 is an equidigital number, since it uses as much as digits as its factorization.

21629642731673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27433728, while the sum is 59.

The spelling of 21629642731673 in words is "twenty-one trillion, six hundred twenty-nine billion, six hundred forty-two million, seven hundred thirty-one thousand, six hundred seventy-three".