21601625007451 has 2 divisors, whose sum is σ = 21601625007452. Its totient is φ = 21601625007450.

The previous prime is 21601625007409. The next prime is 21601625007467. The reversal of 21601625007451 is 15470052610612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21601625007451 - 2⁹ = 21601625006939 is a prime.

It is not a weakly prime, because it can be changed into another prime (21601625007491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10800812503725 + 10800812503726.

It is an arithmetic number, because the mean of its divisors is an integer number (10800812503726).

Almost surely, 2^{21601625007451} is an apocalyptic number.

21601625007451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21601625007451 is an equidigital number, since it uses as much as digits as its factorization.

21601625007451 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 40.

The spelling of 21601625007451 in words is "twenty-one trillion, six hundred one billion, six hundred twenty-five million, seven thousand, four hundred fifty-one".