628275518921 has 4 divisors (see below), whose sum is σ = 628454162052. Its totient is φ = 628096875792.

The previous prime is 628275518911. The next prime is 628275518971. The reversal of 628275518921 is 129815572826.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129815572826 = 2 ⋅64907786413.

It can be written as a sum of positive squares in 2 ways, for example, as 513802240000 + 114473278921 = 716800^2 + 338339^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-628275518921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628275518911) 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, 89316290 + ... + 89323323.

It is an arithmetic number, because the mean of its divisors is an integer number (157113540513).

Almost surely, 2^628275518921 is an apocalyptic number.

It is an amenable number.

628275518921 is a deficient number, since it is larger than the sum of its proper divisors (178643131).

628275518921 is a wasteful number, since it uses less digits than its factorization.

628275518921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178643130.

The product of its digits is 4838400, while the sum is 56.

The spelling of 628275518921 in words is "six hundred twenty-eight billion, two hundred seventy-five million, five hundred eighteen thousand, nine hundred twenty-one".