644242498 has 16 divisors (see below), whose sum is σ = 981097920. Its totient is φ = 317220400.

The previous prime is 644242477. The next prime is 644242499. The reversal of 644242498 is 894242446.

It is not an unprimeable number, because it can be changed into a prime (644242499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155433 + ... + 159523.

It is an arithmetic number, because the mean of its divisors is an integer number (61318620).

Almost surely, 2^644242498 is an apocalyptic number.

644242498 is a deficient number, since it is larger than the sum of its proper divisors (336855422).

644242498 is a wasteful number, since it uses less digits than its factorization.

644242498 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5273.

The product of its digits is 442368, while the sum is 43.

The square root of 644242498 is about 25381.9325111387. The cubic root of 644242498 is about 863.6738890227.

The spelling of 644242498 in words is "six hundred forty-four million, two hundred forty-two thousand, four hundred ninety-eight".