668428551 has 24 divisors (see below), whose sum is σ = 1151942640. Its totient is φ = 381958416.

The previous prime is 668428549. The next prime is 668428573. The reversal of 668428551 is 155824866.

It is not a de Polignac number, because 668428551 - 2¹ = 668428549 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 668428497 and 668428506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668428591) 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 23 ways as a sum of consecutive naturals, for example, 251296 + ... + 253941.

It is an arithmetic number, because the mean of its divisors is an integer number (47997610).

Almost surely, 2^668428551 is an apocalyptic number.

668428551 is a deficient number, since it is larger than the sum of its proper divisors (483514089).

668428551 is a wasteful number, since it uses less digits than its factorization.

668428551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505260 (or 505247 counting only the distinct ones).

The product of its digits is 460800, while the sum is 45.

The square root of 668428551 is about 25853.9852053798. The cubic root of 668428551 is about 874.3493616472.

The spelling of 668428551 in words is "six hundred sixty-eight million, four hundred twenty-eight thousand, five hundred fifty-one".