646513407 has 24 divisors (see below), whose sum is σ = 971268480. Its totient is φ = 429750360.

The previous prime is 646513393. The next prime is 646513421. The reversal of 646513407 is 704315646.

It is a happy number.

646513407 is a `hidden beast` number, since 646 + 5 + 1 + 3 + 4 + 0 + 7 = 666.

646513407 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (646513393) and next prime (646513421).

It is not a de Polignac number, because 646513407 - 2¹⁶ = 646447871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646513447) 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, 83532 + ... + 90942.

It is an arithmetic number, because the mean of its divisors is an integer number (40469520).

Almost surely, 2^646513407 is an apocalyptic number.

646513407 is a deficient number, since it is larger than the sum of its proper divisors (324755073).

646513407 is an equidigital number, since it uses as much as digits as its factorization.

646513407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7785 (or 7773 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 646513407 is about 25426.6279124858. The cubic root of 646513407 is about 864.6874953412.

The spelling of 646513407 in words is "six hundred forty-six million, five hundred thirteen thousand, four hundred seven".