628638872 has 8 divisors (see below), whose sum is σ = 1178697900. Its totient is φ = 314319432.

The previous prime is 628638859. The next prime is 628638877. The reversal of 628638872 is 278836826.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 628638872.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628638877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39289922 + ... + 39289937.

Almost surely, 2^628638872 is an apocalyptic number.

It is an amenable number.

628638872 is a deficient number, since it is larger than the sum of its proper divisors (550059028).

628638872 is a wasteful number, since it uses less digits than its factorization.

628638872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78579865 (or 78579861 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 50.

The square root of 628638872 is about 25072.6718161428. The cubic root of 628638872 is about 856.6440657451.

The spelling of 628638872 in words is "six hundred twenty-eight million, six hundred thirty-eight thousand, eight hundred seventy-two".