6665690647 has 24 divisors (see below), whose sum is σ = 8466256512. Its totient is φ = 5189511600.

The previous prime is 6665690617. The next prime is 6665690683. The reversal of 6665690647 is 7460965666.

It is a de Polignac number, because none of the positive numbers 2^k-6665690647 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665690617) 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, 697572 + ... + 707062.

It is an arithmetic number, because the mean of its divisors is an integer number (352760688).

Almost surely, 2^6665690647 is an apocalyptic number.

6665690647 is a deficient number, since it is larger than the sum of its proper divisors (1800565865).

6665690647 is a wasteful number, since it uses less digits than its factorization.

6665690647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10819 (or 10812 counting only the distinct ones).

The product of its (nonzero) digits is 9797760, while the sum is 55.

The square root of 6665690647 is about 81643.6809985929. The cubic root of 6665690647 is about 1881.9802063123.

The spelling of 6665690647 in words is "six billion, six hundred sixty-five million, six hundred ninety thousand, six hundred forty-seven".