21724445635451 has 16 divisors (see below), whose sum is σ = 23633003599296. Its totient is φ = 19849978509696.

The previous prime is 21724445635439. The next prime is 21724445635513. The reversal of 21724445635451 is 15453654442712.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21724445635451 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 21724445635393 and 21724445635402.

It is not an unprimeable number, because it can be changed into a prime (21724445635421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 467480 + ... + 6608133.

It is an arithmetic number, because the mean of its divisors is an integer number (1477062724956).

Almost surely, 2^{21724445635451} is an apocalyptic number.

21724445635451 is a deficient number, since it is larger than the sum of its proper divisors (1908557963845).

21724445635451 is a wasteful number, since it uses less digits than its factorization.

21724445635451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7078022.

The product of its digits is 16128000, while the sum is 53.

The spelling of 21724445635451 in words is "twenty-one trillion, seven hundred twenty-four billion, four hundred forty-five million, six hundred thirty-five thousand, four hundred fifty-one".