628645681 has 8 divisors (see below), whose sum is σ = 643623200. Its totient is φ = 613684512.

The previous prime is 628645663. The next prime is 628645711. The reversal of 628645681 is 186546826.

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 628645681 - 2¹³ = 628637489 is a prime.

It is a super-2 number, since 2×628645681² = 790390784479907522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628645631) 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, 112645 + ... + 118093.

It is an arithmetic number, because the mean of its divisors is an integer number (80452900).

Almost surely, 2^628645681 is an apocalyptic number.

It is an amenable number.

628645681 is a deficient number, since it is larger than the sum of its proper divisors (14977519).

628645681 is a wasteful number, since it uses less digits than its factorization.

628645681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8175.

The product of its digits is 552960, while the sum is 46.

The square root of 628645681 is about 25072.8076010645. The cubic root of 628645681 is about 856.6471586010.

The spelling of 628645681 in words is "six hundred twenty-eight million, six hundred forty-five thousand, six hundred eighty-one".