685995137 has 4 divisors (see below), whose sum is σ = 687938820. Its totient is φ = 684051456.

The previous prime is 685995119. The next prime is 685995161. The reversal of 685995137 is 731599586.

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 176996416 + 508998721 = 13304^2 + 22561^2 .

It is a cyclic number.

It is not a de Polignac number, because 685995137 - 2¹² = 685991041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685995637) 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, 971312 + ... + 972017.

It is an arithmetic number, because the mean of its divisors is an integer number (171984705).

Almost surely, 2^685995137 is an apocalyptic number.

It is an amenable number.

685995137 is a deficient number, since it is larger than the sum of its proper divisors (1943683).

685995137 is a wasteful number, since it uses less digits than its factorization.

685995137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943682.

The product of its digits is 2041200, while the sum is 53.

The square root of 685995137 is about 26191.5088721517. The cubic root of 685995137 is about 881.9426509092.

The spelling of 685995137 in words is "six hundred eighty-five million, nine hundred ninety-five thousand, one hundred thirty-seven".