628954221 has 16 divisors (see below), whose sum is σ = 961261184. Its totient is φ = 358331904.

The previous prime is 628954211. The next prime is 628954229. The reversal of 628954221 is 122459826.

It is not a de Polignac number, because 628954221 - 2¹⁰ = 628953197 is a prime.

It is a super-2 number, since 2×628954221² = 791166824227433682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 628954221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628954229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37360 + ... + 51513.

It is an arithmetic number, because the mean of its divisors is an integer number (60078824).

Almost surely, 2^628954221 is an apocalyptic number.

It is an amenable number.

628954221 is a deficient number, since it is larger than the sum of its proper divisors (332306963).

628954221 is a wasteful number, since it uses less digits than its factorization.

628954221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89220.

The product of its digits is 69120, while the sum is 39.

The square root of 628954221 is about 25078.9597272295. The cubic root of 628954221 is about 856.7872834720.

The spelling of 628954221 in words is "six hundred twenty-eight million, nine hundred fifty-four thousand, two hundred twenty-one".