628813321 has 4 divisors (see below), whose sum is σ = 629407044. Its totient is φ = 628219600.

The previous prime is 628813319. The next prime is 628813337. The reversal of 628813321 is 123318826.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123318826 = 2 ⋅61659413.

It can be written as a sum of positive squares in 2 ways, for example, as 447534025 + 181279296 = 21155^2 + 13464^2 .

It is a cyclic number.

It is not a de Polignac number, because 628813321 - 2¹ = 628813319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (628813301) 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, 295270 + ... + 297391.

It is an arithmetic number, because the mean of its divisors is an integer number (157351761).

Almost surely, 2^628813321 is an apocalyptic number.

It is an amenable number.

628813321 is a deficient number, since it is larger than the sum of its proper divisors (593723).

628813321 is a wasteful number, since it uses less digits than its factorization.

628813321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593722.

The product of its digits is 13824, while the sum is 34.

The square root of 628813321 is about 25076.1504422030. The cubic root of 628813321 is about 856.7232987706.

The spelling of 628813321 in words is "six hundred twenty-eight million, eight hundred thirteen thousand, three hundred twenty-one".