628978916 has 6 divisors (see below), whose sum is σ = 1100713110. Its totient is φ = 314489456.

The previous prime is 628978843. The next prime is 628978921. The reversal of 628978916 is 619879826.

It can be written as a sum of positive squares in only one way, i.e., 357058816 + 271920100 = 18896^2 + 16490^2 .

It is a super-2 number, since 2×628978916² = 791228953545070112, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78622361 + ... + 78622368.

It is an arithmetic number, because the mean of its divisors is an integer number (183452185).

Almost surely, 2^628978916 is an apocalyptic number.

It is an amenable number.

628978916 is a deficient number, since it is larger than the sum of its proper divisors (471734194).

628978916 is a wasteful number, since it uses less digits than its factorization.

628978916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157244733 (or 157244731 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 56.

The square root of 628978916 is about 25079.4520673798. The cubic root of 628978916 is about 856.7984968398.

The spelling of 628978916 in words is "six hundred twenty-eight million, nine hundred seventy-eight thousand, nine hundred sixteen".