21653040006451 has 4 divisors (see below), whose sum is σ = 24746331435952. Its totient is φ = 18559748576952.

The previous prime is 21653040006421. The next prime is 21653040006497. The reversal of 21653040006451 is 15460004035612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21653040006451 - 2⁵ = 21653040006419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21653040006451.

It is not an unprimeable number, because it can be changed into a prime (21653040006421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1546645714740 + ... + 1546645714753.

It is an arithmetic number, because the mean of its divisors is an integer number (6186582858988).

Almost surely, 2^{21653040006451} is an apocalyptic number.

21653040006451 is a deficient number, since it is larger than the sum of its proper divisors (3093291429501).

21653040006451 is an equidigital number, since it uses as much as digits as its factorization.

21653040006451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093291429500.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 21653040006451 in words is "twenty-one trillion, six hundred fifty-three billion, forty million, six thousand, four hundred fifty-one".