644608495 has 8 divisors (see below), whose sum is σ = 776939184. Its totient is φ = 513414144.

The previous prime is 644608493. The next prime is 644608507. The reversal of 644608495 is 594806446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644608495 - 2¹ = 644608493 is a prime.

It is a super-2 number, since 2×644608495² = 831040223652330050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644608493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 282834 + ... + 285103.

It is an arithmetic number, because the mean of its divisors is an integer number (97117398).

Almost surely, 2^644608495 is an apocalyptic number.

644608495 is a deficient number, since it is larger than the sum of its proper divisors (132330689).

644608495 is a wasteful number, since it uses less digits than its factorization.

644608495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568169.

The product of its (nonzero) digits is 829440, while the sum is 46.

The square root of 644608495 is about 25389.1412812643. The cubic root of 644608495 is about 863.8374103741.

The spelling of 644608495 in words is "six hundred forty-four million, six hundred eight thousand, four hundred ninety-five".