644503732752 has 160 divisors (see below), whose sum is σ = 1956439351296. Its totient is φ = 180786355200.

The previous prime is 644503732723. The next prime is 644503732759. The reversal of 644503732752 is 257237305446.

It is a super-2 number, since 2×644503732752² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (644503732759) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 479533 + ... + 1232460.

Almost surely, 2^644503732752 is an apocalyptic number.

644503732752 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

644503732752 is an abundant number, since it is smaller than the sum of its proper divisors (1311935618544).

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

644503732752 is a wasteful number, since it uses less digits than its factorization.

644503732752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1712069 (or 1712063 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 48.

The spelling of 644503732752 in words is "six hundred forty-four billion, five hundred three million, seven hundred thirty-two thousand, seven hundred fifty-two".