628821293 has 4 divisors (see below), whose sum is σ = 643445088. Its totient is φ = 614197500.

The previous prime is 628821289. The next prime is 628821341. The reversal of 628821293 is 392128826.

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, and also an emirpimes, since its reverse is a distinct semiprime: 392128826 = 2 ⋅196064413.

It is a cyclic number.

It is not a de Polignac number, because 628821293 - 2² = 628821289 is a prime.

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 628821293.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628821793) 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, 7311833 + ... + 7311918.

It is an arithmetic number, because the mean of its divisors is an integer number (160861272).

Almost surely, 2^628821293 is an apocalyptic number.

It is an amenable number.

628821293 is a deficient number, since it is larger than the sum of its proper divisors (14623795).

628821293 is a wasteful number, since it uses less digits than its factorization.

628821293 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14623794.

The product of its digits is 82944, while the sum is 41.

The square root of 628821293 is about 25076.3093975170. The cubic root of 628821293 is about 856.7269192247.

The spelling of 628821293 in words is "six hundred twenty-eight million, eight hundred twenty-one thousand, two hundred ninety-three".