16921944513 has 6 divisors (see below), whose sum is σ = 24442808754. Its totient is φ = 11281296336.

The previous prime is 16921944511. The next prime is 16921944527. The reversal of 16921944513 is 31544912961.

16921944513 is a `hidden beast` number, since 1 + 6 + 9 + 2 + 194 + 451 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16562917809 + 359026704 = 128697^2 + 18948^2 .

It is not a de Polignac number, because 16921944513 - 2¹ = 16921944511 is a prime.

It is a super-2 number, since 2×16921944513² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16921944511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 940108020 + ... + 940108037.

It is an arithmetic number, because the mean of its divisors is an integer number (4073801459).

Almost surely, 2^16921944513 is an apocalyptic number.

It is an amenable number.

16921944513 is a deficient number, since it is larger than the sum of its proper divisors (7520864241).

16921944513 is a wasteful number, since it uses less digits than its factorization.

16921944513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1880216063 (or 1880216060 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The spelling of 16921944513 in words is "sixteen billion, nine hundred twenty-one million, nine hundred forty-four thousand, five hundred thirteen".