647499944 has 128 divisors (see below), whose sum is σ = 1599575040. Its totient is φ = 238436352.

The previous prime is 647499943. The next prime is 647499953. The reversal of 647499944 is 449994746.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (56).

It is a self number, because there is not a number n which added to its sum of digits gives 647499944.

It is not an unprimeable number, because it can be changed into a prime (647499943) 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, 1398257 + ... + 1398719.

It is an arithmetic number, because the mean of its divisors is an integer number (12496680).

Almost surely, 2^647499944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647499944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799787520).

647499944 is an abundant number, since it is smaller than the sum of its proper divisors (952075096).

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

647499944 is a wasteful number, since it uses less digits than its factorization.

647499944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619 (or 615 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 56.

The square root of 647499944 is about 25446.0201996304. The cubic root of 647499944 is about 865.1270905959.

The spelling of 647499944 in words is "six hundred forty-seven million, four hundred ninety-nine thousand, nine hundred forty-four".