628775731 has 4 divisors (see below), whose sum is σ = 634340232. Its totient is φ = 623211232.

The previous prime is 628775717. The next prime is 628775747. The reversal of 628775731 is 137577826.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137577826 = 2 ⋅68788913.

It is a cyclic number.

It is not a de Polignac number, because 628775731 - 2¹³ = 628767539 is a prime.

It is a super-2 number, since 2×628775731² = 790717839789168722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628775701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782081 + ... + 2782306.

It is an arithmetic number, because the mean of its divisors is an integer number (158585058).

Almost surely, 2^628775731 is an apocalyptic number.

628775731 is a deficient number, since it is larger than the sum of its proper divisors (5564501).

628775731 is a wasteful number, since it uses less digits than its factorization.

628775731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5564500.

The product of its digits is 493920, while the sum is 46.

The square root of 628775731 is about 25075.4009140432. The cubic root of 628775731 is about 856.7062269998.

The spelling of 628775731 in words is "six hundred twenty-eight million, seven hundred seventy-five thousand, seven hundred thirty-one".