628647440 has 20 divisors (see below), whose sum is σ = 1461605484. Its totient is φ = 251458944.

The previous prime is 628647407. The next prime is 628647449. The reversal of 628647440 is 44746826.

It can be written as a sum of positive squares in 2 ways, for example, as 487703056 + 140944384 = 22084^2 + 11872^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (628647449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3928967 + ... + 3929126.

Almost surely, 2^628647440 is an apocalyptic number.

It is an amenable number.

628647440 is an abundant number, since it is smaller than the sum of its proper divisors (832958044).

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

628647440 is a wasteful number, since it uses less digits than its factorization.

628647440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7858106 (or 7858100 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 41.

The square root of 628647440 is about 25072.8426788827. The cubic root of 628647440 is about 856.6479575889.

The spelling of 628647440 in words is "six hundred twenty-eight million, six hundred forty-seven thousand, four hundred forty".