646900651 has 4 divisors (see below), whose sum is σ = 669207600. Its totient is φ = 624593704.

The previous prime is 646900627. The next prime is 646900673. The reversal of 646900651 is 156009646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 646900651 - 2¹⁵ = 646867883 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 646900651.

It is not an unprimeable number, because it can be changed into a prime (646903651) 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, 11153431 + ... + 11153488.

It is an arithmetic number, because the mean of its divisors is an integer number (167301900).

Almost surely, 2^646900651 is an apocalyptic number.

646900651 is a deficient number, since it is larger than the sum of its proper divisors (22306949).

646900651 is a wasteful number, since it uses less digits than its factorization.

646900651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22306948.

The product of its (nonzero) digits is 38880, while the sum is 37.

The square root of 646900651 is about 25434.2417028698. The cubic root of 646900651 is about 864.8601023378.

The spelling of 646900651 in words is "six hundred forty-six million, nine hundred thousand, six hundred fifty-one".