685400539 has 4 divisors (see below), whose sum is σ = 685532440. Its totient is φ = 685268640.

The previous prime is 685400533. The next prime is 685400549. The reversal of 685400539 is 935004586.

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

It is a cyclic number.

It is not a de Polignac number, because 685400539 - 2³ = 685400531 is a prime.

It is a super-2 number, since 2×685400539² = 939547797722981042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685400531) 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, 57822 + ... + 68659.

It is an arithmetic number, because the mean of its divisors is an integer number (171383110).

Almost surely, 2^685400539 is an apocalyptic number.

685400539 is a deficient number, since it is larger than the sum of its proper divisors (131901).

685400539 is a wasteful number, since it uses less digits than its factorization.

685400539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131900.

The product of its (nonzero) digits is 129600, while the sum is 40.

The square root of 685400539 is about 26180.1554426249. The cubic root of 685400539 is about 881.6877643013.

The spelling of 685400539 in words is "six hundred eighty-five million, four hundred thousand, five hundred thirty-nine".