21072926459621 has 2 divisors, whose sum is σ = 21072926459622. Its totient is φ = 21072926459620.

The previous prime is 21072926459561. The next prime is 21072926459657. The reversal of 21072926459621 is 12695462927012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20640075628225 + 432850831396 = 4543135^2 + 657914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21072926459621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21072926452621) 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, 10536463229810 + 10536463229811.

It is an arithmetic number, because the mean of its divisors is an integer number (10536463229811).

Almost surely, 2^{21072926459621} is an apocalyptic number.

It is an amenable number.

21072926459621 is a deficient number, since it is larger than the sum of its proper divisors (1).

21072926459621 is an equidigital number, since it uses as much as digits as its factorization.

21072926459621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6531840, while the sum is 56.

The spelling of 21072926459621 in words is "twenty-one trillion, seventy-two billion, nine hundred twenty-six million, four hundred fifty-nine thousand, six hundred twenty-one".