664049751 has 4 divisors (see below), whose sum is σ = 885399672. Its totient is φ = 442699832.

The previous prime is 664049689. The next prime is 664049761. The reversal of 664049751 is 157940466.

664049751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 664049751 - 2²⁵ = 630495319 is a prime.

It is a super-3 number, since 3×664049751³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664049761) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110674956 + ... + 110674961.

It is an arithmetic number, because the mean of its divisors is an integer number (221349918).

Almost surely, 2^664049751 is an apocalyptic number.

664049751 is a deficient number, since it is larger than the sum of its proper divisors (221349921).

664049751 is a wasteful number, since it uses less digits than its factorization.

664049751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221349920.

The product of its (nonzero) digits is 181440, while the sum is 42.

The square root of 664049751 is about 25769.1627919884. The cubic root of 664049751 is about 872.4359226402.

The spelling of 664049751 in words is "six hundred sixty-four million, forty-nine thousand, seven hundred fifty-one".