780684161 has 4 divisors (see below), whose sum is σ = 793482324. Its totient is φ = 767886000.

The previous prime is 780684133. The next prime is 780684169. The reversal of 780684161 is 161486087.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161486087 = 7 ⋅23069441.

It can be written as a sum of positive squares in 2 ways, for example, as 254211136 + 526473025 = 15944^2 + 22945^2 .

It is a cyclic number.

It is not a de Polignac number, because 780684161 - 2⁶ = 780684097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (780684169) 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, 6398990 + ... + 6399111.

It is an arithmetic number, because the mean of its divisors is an integer number (198370581).

Almost surely, 2^780684161 is an apocalyptic number.

It is an amenable number.

780684161 is a deficient number, since it is larger than the sum of its proper divisors (12798163).

780684161 is a wasteful number, since it uses less digits than its factorization.

780684161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12798162.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 780684161 is about 27940.7258495552. The cubic root of 780684161 is about 920.7854669622.

The spelling of 780684161 in words is "seven hundred eighty million, six hundred eighty-four thousand, one hundred sixty-one".