646949787 has 16 divisors (see below), whose sum is σ = 942539520. Its totient is φ = 391456800.

The previous prime is 646949759. The next prime is 646949801. The reversal of 646949787 is 787949646.

It is not a de Polignac number, because 646949787 - 2⁸ = 646949531 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 646949787.

It is not an unprimeable number, because it can be changed into a prime (646949717) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5289 + ... + 36357.

It is an arithmetic number, because the mean of its divisors is an integer number (58908720).

Almost surely, 2^646949787 is an apocalyptic number.

646949787 is a deficient number, since it is larger than the sum of its proper divisors (295589733).

646949787 is a wasteful number, since it uses less digits than its factorization.

646949787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31714.

The product of its digits is 18289152, while the sum is 60.

The square root of 646949787 is about 25435.2076264378. The cubic root of 646949787 is about 864.8819988944.

The spelling of 646949787 in words is "six hundred forty-six million, nine hundred forty-nine thousand, seven hundred eighty-seven".