21506974513 has 8 divisors (see below), whose sum is σ = 22701988800. Its totient is φ = 20318267088.

The previous prime is 21506974507. The next prime is 21506974529. The reversal of 21506974513 is 31547960512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21506974513 - 2¹⁷ = 21506843441 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21506974513.

It is not an unprimeable number, because it can be changed into a prime (21506974913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1569706 + ... + 1583347.

It is an arithmetic number, because the mean of its divisors is an integer number (2837748600).

Almost surely, 2^21506974513 is an apocalyptic number.

It is an amenable number.

21506974513 is a deficient number, since it is larger than the sum of its proper divisors (1195014287).

21506974513 is a wasteful number, since it uses less digits than its factorization.

21506974513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3153431.

The product of its (nonzero) digits is 226800, while the sum is 43.

The spelling of 21506974513 in words is "twenty-one billion, five hundred six million, nine hundred seventy-four thousand, five hundred thirteen".