681837169 has 4 divisors (see below), whose sum is σ = 734286196. Its totient is φ = 629388144.

The previous prime is 681837137. The next prime is 681837251. The reversal of 681837169 is 961738186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 961738186 = 2 ⋅480869093.

It can be written as a sum of positive squares in 2 ways, for example, as 100400400 + 581436769 = 10020^2 + 24113^2 .

It is a cyclic number.

It is not a de Polignac number, because 681837169 - 2⁵ = 681837137 is a prime.

It is a super-2 number, since 2×681837169² = 929803850059869122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681837109) 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, 26224494 + ... + 26224519.

It is an arithmetic number, because the mean of its divisors is an integer number (183571549).

Almost surely, 2^681837169 is an apocalyptic number.

It is an amenable number.

681837169 is a deficient number, since it is larger than the sum of its proper divisors (52449027).

681837169 is a wasteful number, since it uses less digits than its factorization.

681837169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52449026.

The product of its digits is 435456, while the sum is 49.

The square root of 681837169 is about 26112.0119676750. The cubic root of 681837169 is about 880.1571555586.

The spelling of 681837169 in words is "six hundred eighty-one million, eight hundred thirty-seven thousand, one hundred sixty-nine".