21107521451 has 2 divisors, whose sum is σ = 21107521452. Its totient is φ = 21107521450.

The previous prime is 21107521433. The next prime is 21107521531. The reversal of 21107521451 is 15412570112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21107521451 - 2²⁶ = 21040412587 is a prime.

It is not a weakly prime, because it can be changed into another prime (21107527451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10553760725 + 10553760726.

It is an arithmetic number, because the mean of its divisors is an integer number (10553760726).

Almost surely, 2^21107521451 is an apocalyptic number.

21107521451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21107521451 is an equidigital number, since it uses as much as digits as its factorization.

21107521451 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2800, while the sum is 29.

The spelling of 21107521451 in words is "twenty-one billion, one hundred seven million, five hundred twenty-one thousand, four hundred fifty-one".