628639826 has 4 divisors (see below), whose sum is σ = 942959742. Its totient is φ = 314319912.

The previous prime is 628639811. The next prime is 628639849. The reversal of 628639826 is 628936826.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 584430625 + 44209201 = 24175^2 + 6649^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157159955 + ... + 157159958.

Almost surely, 2^628639826 is an apocalyptic number.

628639826 is a deficient number, since it is larger than the sum of its proper divisors (314319916).

628639826 is a wasteful number, since it uses less digits than its factorization.

628639826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314319915.

The product of its digits is 1492992, while the sum is 50.

The square root of 628639826 is about 25072.6908408332. The cubic root of 628639826 is about 856.6444990824.

The spelling of 628639826 in words is "six hundred twenty-eight million, six hundred thirty-nine thousand, eight hundred twenty-six".