646504655 has 4 divisors (see below), whose sum is σ = 775805592. Its totient is φ = 517203720.

The previous prime is 646504603. The next prime is 646504673. The reversal of 646504655 is 556405646.

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

It is not a de Polignac number, because 646504655 - 2⁶ = 646504591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64650461 + ... + 64650470.

It is an arithmetic number, because the mean of its divisors is an integer number (193951398).

Almost surely, 2^646504655 is an apocalyptic number.

646504655 is a deficient number, since it is larger than the sum of its proper divisors (129300937).

646504655 is a wasteful number, since it uses less digits than its factorization.

646504655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129300936.

The product of its (nonzero) digits is 432000, while the sum is 41.

The square root of 646504655 is about 25426.4558088618. The cubic root of 646504655 is about 864.6835934994.

Subtracting from 646504655 its reverse (556405646), we obtain a palindrome (90099009).

The spelling of 646504655 in words is "six hundred forty-six million, five hundred four thousand, six hundred fifty-five".