686256401 has 4 divisors (see below), whose sum is σ = 702994404. Its totient is φ = 669518400.

The previous prime is 686256397. The next prime is 686256419. The reversal of 686256401 is 104652686.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 42315025 + 643941376 = 6505^2 + 25376^2 .

It is a cyclic number.

It is not a de Polignac number, because 686256401 - 2² = 686256397 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686256491) 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, 8368940 + ... + 8369021.

It is an arithmetic number, because the mean of its divisors is an integer number (175748601).

Almost surely, 2^686256401 is an apocalyptic number.

It is an amenable number.

686256401 is a deficient number, since it is larger than the sum of its proper divisors (16738003).

686256401 is a wasteful number, since it uses less digits than its factorization.

686256401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16738002.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 686256401 is about 26196.4959679725. The cubic root of 686256401 is about 882.0546004972.

The spelling of 686256401 in words is "six hundred eighty-six million, two hundred fifty-six thousand, four hundred one".