669921898 has 8 divisors (see below), whose sum is σ = 1012112640. Its totient is φ = 332551020.

The previous prime is 669921881. The next prime is 669921899. The reversal of 669921898 is 898129966.

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

It is not an unprimeable number, because it can be changed into a prime (669921899) 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, 1204618 + ... + 1205173.

It is an arithmetic number, because the mean of its divisors is an integer number (126514080).

Almost surely, 2^669921898 is an apocalyptic number.

669921898 is a deficient number, since it is larger than the sum of its proper divisors (342190742).

669921898 is a wasteful number, since it uses less digits than its factorization.

669921898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2409932.

The product of its digits is 3359232, while the sum is 58.

The square root of 669921898 is about 25882.8494953705. The cubic root of 669921898 is about 875.0000100136. Note that the first 4 decimals are identical.

The spelling of 669921898 in words is "six hundred sixty-nine million, nine hundred twenty-one thousand, eight hundred ninety-eight".