644231460 has 48 divisors (see below), whose sum is σ = 1862042112. Its totient is φ = 166252800.

The previous prime is 644231447. The next prime is 644231477. The reversal of 644231460 is 64132446.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 171321 + ... + 175040.

It is an arithmetic number, because the mean of its divisors is an integer number (38792544).

Almost surely, 2^644231460 is an apocalyptic number.

644231460 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644231460 is an abundant number, since it is smaller than the sum of its proper divisors (1217810652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644231460 is a wasteful number, since it uses less digits than its factorization.

644231460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346404 (or 346402 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 644231460 is about 25381.7150720750. The cubic root of 644231460 is about 863.6689564666.

The spelling of 644231460 in words is "six hundred forty-four million, two hundred thirty-one thousand, four hundred sixty".