810168749 has 4 divisors (see below), whose sum is σ = 872489436. Its totient is φ = 747848064.

The previous prime is 810168731. The next prime is 810168781. The reversal of 810168749 is 947861018.

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 408767524 + 401401225 = 20218^2 + 20035^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-810168749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (810168349) 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, 31160324 + ... + 31160349.

It is an arithmetic number, because the mean of its divisors is an integer number (218122359).

Almost surely, 2^810168749 is an apocalyptic number.

It is an amenable number.

810168749 is a deficient number, since it is larger than the sum of its proper divisors (62320687).

810168749 is a wasteful number, since it uses less digits than its factorization.

810168749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62320686.

The product of its (nonzero) digits is 96768, while the sum is 44.

The square root of 810168749 is about 28463.4634048634. The cubic root of 810168749 is about 932.2344809182.

The spelling of 810168749 in words is "eight hundred ten million, one hundred sixty-eight thousand, seven hundred forty-nine".