664999899 has 8 divisors (see below), whose sum is σ = 917241360. Its totient is φ = 428045856.

The previous prime is 664999891. The next prime is 664999903. The reversal of 664999899 is 998999466.

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

It is not a de Polignac number, because 664999899 - 2³ = 664999891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (664999891) 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, 3821752 + ... + 3821925.

It is an arithmetic number, because the mean of its divisors is an integer number (114655170).

Almost surely, 2^664999899 is an apocalyptic number.

664999899 is a deficient number, since it is larger than the sum of its proper divisors (252241461).

664999899 is a wasteful number, since it uses less digits than its factorization.

664999899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7643709.

The product of its digits is 68024448, while the sum is 69.

The square root of 664999899 is about 25787.5919581492. The cubic root of 664999899 is about 872.8518293291.

The spelling of 664999899 in words is "six hundred sixty-four million, nine hundred ninety-nine thousand, eight hundred ninety-nine".