6516969921 has 24 divisors (see below), whose sum is σ = 11736189504. Its totient is φ = 3385438560.

The previous prime is 6516969919. The next prime is 6516969971. The reversal of 6516969921 is 1299696156.

It is not a de Polignac number, because 6516969921 - 2¹ = 6516969919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6516969911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4701306 + ... + 4702691.

It is an arithmetic number, because the mean of its divisors is an integer number (489007896).

Almost surely, 2^6516969921 is an apocalyptic number.

It is an amenable number.

6516969921 is a deficient number, since it is larger than the sum of its proper divisors (5219219583).

6516969921 is a wasteful number, since it uses less digits than its factorization.

6516969921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9404021 (or 9404018 counting only the distinct ones).

The product of its digits is 1574640, while the sum is 54.

The square root of 6516969921 is about 80727.7518639037. The cubic root of 6516969921 is about 1867.8782803862.

The spelling of 6516969921 in words is "six billion, five hundred sixteen million, nine hundred sixty-nine thousand, nine hundred twenty-one".