686656157 has 4 divisors (see below), whose sum is σ = 749079456. Its totient is φ = 624232860.

The previous prime is 686656109. The next prime is 686656183. The reversal of 686656157 is 751656686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 686656157 - 2¹⁴ = 686639773 is a prime.

It is a super-3 number, since 3×686656157³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686656057) 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, 31211633 + ... + 31211654.

It is an arithmetic number, because the mean of its divisors is an integer number (187269864).

Almost surely, 2^686656157 is an apocalyptic number.

It is an amenable number.

686656157 is a deficient number, since it is larger than the sum of its proper divisors (62423299).

686656157 is a wasteful number, since it uses less digits than its factorization.

686656157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62423298.

The product of its digits is 1814400, while the sum is 50.

The square root of 686656157 is about 26204.1248088922. The cubic root of 686656157 is about 882.2258378433.

The spelling of 686656157 in words is "six hundred eighty-six million, six hundred fifty-six thousand, one hundred fifty-seven".