644484457 has 8 divisors (see below), whose sum is σ = 656553600. Its totient is φ = 632487504.

The previous prime is 644484439. The next prime is 644484461. The reversal of 644484457 is 754484446.

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

It is not a de Polignac number, because 644484457 - 2⁷ = 644484329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644484497) 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, 144 + ... + 35902.

It is an arithmetic number, because the mean of its divisors is an integer number (82069200).

Almost surely, 2^644484457 is an apocalyptic number.

644484457 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

It is an amenable number.

644484457 is a deficient number, since it is larger than the sum of its proper divisors (12069143).

644484457 is a wasteful number, since it uses less digits than its factorization.

644484457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36095.

The product of its digits is 1720320, while the sum is 46.

The square root of 644484457 is about 25386.6984265383. The cubic root of 644484457 is about 863.7819992013.

The spelling of 644484457 in words is "six hundred forty-four million, four hundred eighty-four thousand, four hundred fifty-seven".