764440190405 has 6 divisors (see below), whose sum is σ = 917330574546. Its totient is φ = 611550588288.

The previous prime is 764440190387. The next prime is 764440190471. The reversal of 764440190405 is 504091044467.

It can be written as a sum of positive squares in 3 ways, for example, as 426092164 + 764014098241 = 20642^2 + 874079^2 .

It is not a de Polignac number, because 764440190405 - 2⁶ = 764440190341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1759541 + ... + 2150549.

It is an arithmetic number, because the mean of its divisors is an integer number (152888429091).

Almost surely, 2^764440190405 is an apocalyptic number.

It is an amenable number.

764440190405 is a deficient number, since it is larger than the sum of its proper divisors (152890384141).

764440190405 is an frugal number, since it uses more digits than its factorization.

764440190405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782023 (or 391014 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 764440190405 in words is "seven hundred sixty-four billion, four hundred forty million, one hundred ninety thousand, four hundred five".