780164561 has 12 divisors (see below), whose sum is σ = 907981956. Its totient is φ = 667518720.

The previous prime is 780164537. The next prime is 780164617. The reversal of 780164561 is 165461087.

It can be written as a sum of positive squares in 2 ways, for example, as 389865025 + 390299536 = 19745^2 + 19756^2 .

It is not a de Polignac number, because 780164561 - 2²⁶ = 713055697 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 (780163561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 187580 + ... + 191693.

It is an arithmetic number, because the mean of its divisors is an integer number (75665163).

Almost surely, 2^780164561 is an apocalyptic number.

It is an amenable number.

780164561 is a deficient number, since it is larger than the sum of its proper divisors (127817395).

780164561 is a wasteful number, since it uses less digits than its factorization.

780164561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 379312 (or 379301 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 38.

The square root of 780164561 is about 27931.4260466593. The cubic root of 780164561 is about 920.5811392127.

The spelling of 780164561 in words is "seven hundred eighty million, one hundred sixty-four thousand, five hundred sixty-one".