21021631701457 has 2 divisors, whose sum is σ = 21021631701458. Its totient is φ = 21021631701456.

The previous prime is 21021631701451. The next prime is 21021631701461. The reversal of 21021631701457 is 75410713612012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16421224440721 + 4600407260736 = 4052311^2 + 2144856^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021631701457 - 2¹⁵ = 21021631668689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021631701451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510815850728 + 10510815850729.

It is an arithmetic number, because the mean of its divisors is an integer number (10510815850729).

Almost surely, 2^{21021631701457} is an apocalyptic number.

It is an amenable number.

21021631701457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021631701457 is an equidigital number, since it uses as much as digits as its factorization.

21021631701457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 40.

The spelling of 21021631701457 in words is "twenty-one trillion, twenty-one billion, six hundred thirty-one million, seven hundred one thousand, four hundred fifty-seven".