21202516322451 has 40 divisors (see below), whose sum is σ = 31872722644224. Its totient is φ = 14045989576320.

The previous prime is 21202516322443. The next prime is 21202516322459. The reversal of 21202516322451 is 15422361520212.

21202516322451 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 25 + 163 + 22 + 451 = 666.

It is an interprime number because it is at equal distance from previous prime (21202516322443) and next prime (21202516322459).

It is not a de Polignac number, because 21202516322451 - 2³ = 21202516322443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21202516322459) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 13765021 + ... + 15227633.

Almost surely, 2^{21202516322451} is an apocalyptic number.

21202516322451 is a deficient number, since it is larger than the sum of its proper divisors (10670206321773).

21202516322451 is a wasteful number, since it uses less digits than its factorization.

21202516322451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1463753 (or 1463744 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

Adding to 21202516322451 its reverse (15422361520212), we get a palindrome (36624877842663).

The spelling of 21202516322451 in words is "twenty-one trillion, two hundred two billion, five hundred sixteen million, three hundred twenty-two thousand, four hundred fifty-one".