1644036672 has 56 divisors (see below), whose sum is σ = 4353551872. Its totient is φ = 547545600.

The previous prime is 1644036659. The next prime is 1644036683. The reversal of 1644036672 is 2766304461.

It is a happy number.

It is a super-3 number, since 3×1644036672³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1644036672.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279522 + ... + 285342.

Almost surely, 2^1644036672 is an apocalyptic number.

1644036672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1644036672 is an abundant number, since it is smaller than the sum of its proper divisors (2709515200).

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

1644036672 is a wasteful number, since it uses less digits than its factorization.

1644036672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7307 (or 7297 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 39.

The square root of 1644036672 is about 40546.7220869949. The cubic root of 1644036672 is about 1180.2404642566.

The spelling of 1644036672 in words is "one billion, six hundred forty-four million, thirty-six thousand, six hundred seventy-two".