628557869 has 4 divisors (see below), whose sum is σ = 655886496. Its totient is φ = 601229244.

The previous prime is 628557859. The next prime is 628557871. The reversal of 628557869 is 968755826.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 628557869 - 2¹² = 628553773 is a prime.

It is a super-2 number, since 2×628557869² = 790169989363642322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628557859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13664279 + ... + 13664324.

It is an arithmetic number, because the mean of its divisors is an integer number (163971624).

Almost surely, 2^628557869 is an apocalyptic number.

It is an amenable number.

628557869 is a deficient number, since it is larger than the sum of its proper divisors (27328627).

628557869 is a wasteful number, since it uses less digits than its factorization.

628557869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27328626.

The product of its digits is 7257600, while the sum is 56.

The square root of 628557869 is about 25071.0563997611. The cubic root of 628557869 is about 856.6072699932.

The spelling of 628557869 in words is "six hundred twenty-eight million, five hundred fifty-seven thousand, eight hundred sixty-nine".