764671561 has 8 divisors (see below), whose sum is σ = 768141504. Its totient is φ = 761208720.

The previous prime is 764671559. The next prime is 764671571. The reversal of 764671561 is 165176467.

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

It is a cyclic number.

It is not a de Polignac number, because 764671561 - 2¹ = 764671559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (764671571) 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 7 ways as a sum of consecutive naturals, for example, 376230 + ... + 378256.

It is an arithmetic number, because the mean of its divisors is an integer number (96017688).

Almost surely, 2^764671561 is an apocalyptic number.

It is an amenable number.

764671561 is a deficient number, since it is larger than the sum of its proper divisors (3469943).

764671561 is a wasteful number, since it uses less digits than its factorization.

764671561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3551.

The product of its digits is 211680, while the sum is 43.

The square root of 764671561 is about 27652.6953659132. The cubic root of 764671561 is about 914.4465228481.

The spelling of 764671561 in words is "seven hundred sixty-four million, six hundred seventy-one thousand, five hundred sixty-one".