628117021 has 4 divisors (see below), whose sum is σ = 717848032. Its totient is φ = 538386012.

The previous prime is 628116997. The next prime is 628117031. The reversal of 628117021 is 120711826.

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 628117021 - 2⁵ = 628116989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628117031) 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, 44865495 + ... + 44865508.

It is an arithmetic number, because the mean of its divisors is an integer number (179462008).

Almost surely, 2^628117021 is an apocalyptic number.

It is an amenable number.

628117021 is a deficient number, since it is larger than the sum of its proper divisors (89731011).

628117021 is an equidigital number, since it uses as much as digits as its factorization.

628117021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89731010.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 628117021 is about 25062.2628866589. The cubic root of 628117021 is about 856.4069585920.

Adding to 628117021 its reverse (120711826), we get a palindrome (748828847).

It can be divided in two parts, 628 and 117021, that added together give a 6-th power (117649 = 7⁶).

The spelling of 628117021 in words is "six hundred twenty-eight million, one hundred seventeen thousand, twenty-one".