686392901 has 4 divisors (see below), whose sum is σ = 726768972. Its totient is φ = 646016832.

The previous prime is 686392891. The next prime is 686392991. The reversal of 686392901 is 109293686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 109293686 = 2 ⋅54646843.

It can be written as a sum of positive squares in 2 ways, for example, as 320589025 + 365803876 = 17905^2 + 19126^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686392901 is a prime.

It is a super-2 number, since 2×686392901² = 942270429086391602, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686392991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20188010 + ... + 20188043.

It is an arithmetic number, because the mean of its divisors is an integer number (181692243).

Almost surely, 2^686392901 is an apocalyptic number.

It is an amenable number.

686392901 is a deficient number, since it is larger than the sum of its proper divisors (40376071).

686392901 is a wasteful number, since it uses less digits than its factorization.

686392901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40376070.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 686392901 is about 26199.1011487036. The cubic root of 686392901 is about 882.1130783834.

The spelling of 686392901 in words is "six hundred eighty-six million, three hundred ninety-two thousand, nine hundred one".