764490721 has 16 divisors (see below), whose sum is σ = 851880960. Its totient is φ = 683242560.

The previous prime is 764490689. The next prime is 764490751. The reversal of 764490721 is 127094467.

764490721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 764490721 - 2⁵ = 764490689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (764490751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2191 + ... + 39163.

It is an arithmetic number, because the mean of its divisors is an integer number (53242560).

Almost surely, 2^764490721 is an apocalyptic number.

It is an amenable number.

764490721 is a deficient number, since it is larger than the sum of its proper divisors (87390239).

764490721 is a wasteful number, since it uses less digits than its factorization.

764490721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37056.

The product of its (nonzero) digits is 84672, while the sum is 40.

The square root of 764490721 is about 27649.4253285670. The cubic root of 764490721 is about 914.3744302202.

The spelling of 764490721 in words is "seven hundred sixty-four million, four hundred ninety thousand, seven hundred twenty-one".