664830791 has 4 divisors (see below), whose sum is σ = 665120784. Its totient is φ = 664540800.

The previous prime is 664830773. The next prime is 664830799. The reversal of 664830791 is 197038466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664830791 - 2¹⁴ = 664814407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664830799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141530 + ... + 146151.

It is an arithmetic number, because the mean of its divisors is an integer number (166280196).

Almost surely, 2^664830791 is an apocalyptic number.

664830791 is a deficient number, since it is larger than the sum of its proper divisors (289993).

664830791 is a wasteful number, since it uses less digits than its factorization.

664830791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289992.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 664830791 is about 25784.3128859390. The cubic root of 664830791 is about 872.7778349615. Note that the first 3 decimals are identical.

The spelling of 664830791 in words is "six hundred sixty-four million, eight hundred thirty thousand, seven hundred ninety-one".