249698681 has 16 divisors (see below), whose sum is σ = 262222800. Its totient is φ = 237530880.

The previous prime is 249698641. The next prime is 249698717. The reversal of 249698681 is 186896942.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 12538681 + 237160000 = 3541^2 + 15400^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249698681 is a prime.

It is a super-2 number, since 2×249698681² = 124698862586279522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (249698621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 715295 + ... + 715643.

It is an arithmetic number, because the mean of its divisors is an integer number (16388925).

Almost surely, 2^249698681 is an apocalyptic number.

It is an amenable number.

249698681 is a deficient number, since it is larger than the sum of its proper divisors (12524119).

249698681 is a wasteful number, since it uses less digits than its factorization.

249698681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764.

The product of its digits is 1492992, while the sum is 53.

The square root of 249698681 is about 15801.8568845563. The cubic root of 249698681 is about 629.7073310968.

The spelling of 249698681 in words is "two hundred forty-nine million, six hundred ninety-eight thousand, six hundred eighty-one".