6516643937 has 4 divisors (see below), whose sum is σ = 6668193840. Its totient is φ = 6365094036.

The previous prime is 6516643933. The next prime is 6516643999. The reversal of 6516643937 is 7393466156.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6516643937 - 2² = 6516643933 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6516643933) 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, 75774887 + ... + 75774972.

It is an arithmetic number, because the mean of its divisors is an integer number (1667048460).

Almost surely, 2^6516643937 is an apocalyptic number.

It is an amenable number.

6516643937 is a deficient number, since it is larger than the sum of its proper divisors (151549903).

6516643937 is a wasteful number, since it uses less digits than its factorization.

6516643937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151549902.

The product of its digits is 2449440, while the sum is 50.

The square root of 6516643937 is about 80725.7328055930. The cubic root of 6516643937 is about 1867.8471356163.

The spelling of 6516643937 in words is "six billion, five hundred sixteen million, six hundred forty-three thousand, nine hundred thirty-seven".