668749399 has 8 divisors (see below), whose sum is σ = 676684800. Its totient is φ = 660860256.

The previous prime is 668749363. The next prime is 668749427. The reversal of 668749399 is 993947866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 668749399 - 2⁷ = 668749271 is a prime.

It is a super-2 number, since 2×668749399² = 894451517325722402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668749339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17962 + ... + 40744.

It is an arithmetic number, because the mean of its divisors is an integer number (84585600).

Almost surely, 2^668749399 is an apocalyptic number.

668749399 is a deficient number, since it is larger than the sum of its proper divisors (7935401).

668749399 is a wasteful number, since it uses less digits than its factorization.

668749399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23129.

The product of its digits is 17635968, while the sum is 61.

The square root of 668749399 is about 25860.1894617963. The cubic root of 668749399 is about 874.4892361683.

The spelling of 668749399 in words is "six hundred sixty-eight million, seven hundred forty-nine thousand, three hundred ninety-nine".