628855631 has 2 divisors, whose sum is σ = 628855632. Its totient is φ = 628855630.

The previous prime is 628855621. The next prime is 628855637. The reversal of 628855631 is 136558826.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 628855631 - 2¹⁸ = 628593487 is a prime.

It is a super-2 number, since 2×628855631² = 790918809280816322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628855637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314427815 + 314427816.

It is an arithmetic number, because the mean of its divisors is an integer number (314427816).

Almost surely, 2^628855631 is an apocalyptic number.

628855631 is a deficient number, since it is larger than the sum of its proper divisors (1).

628855631 is an equidigital number, since it uses as much as digits as its factorization.

628855631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 345600, while the sum is 44.

The square root of 628855631 is about 25076.9940582997. The cubic root of 628855631 is about 856.7425133496.

The spelling of 628855631 in words is "six hundred twenty-eight million, eight hundred fifty-five thousand, six hundred thirty-one".