628657631 has 8 divisors (see below), whose sum is σ = 718639104. Its totient is φ = 538719480.

The previous prime is 628657559. The next prime is 628657669. The reversal of 628657631 is 136756826.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 628657631 - 2²² = 624463327 is a prime.

It is a super-2 number, since 2×628657631² = 790420834029064322, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628657231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31106 + ... + 47168.

It is an arithmetic number, because the mean of its divisors is an integer number (89829888).

Almost surely, 2^628657631 is an apocalyptic number.

628657631 is a deficient number, since it is larger than the sum of its proper divisors (89981473).

628657631 is a wasteful number, since it uses less digits than its factorization.

628657631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21661.

The product of its digits is 362880, while the sum is 44.

The square root of 628657631 is about 25073.0459059126. The cubic root of 628657631 is about 856.6525866023.

The spelling of 628657631 in words is "six hundred twenty-eight million, six hundred fifty-seven thousand, six hundred thirty-one".