249686749 has 4 divisors (see below), whose sum is σ = 268893436. Its totient is φ = 230480064.

The previous prime is 249686737. The next prime is 249686753. The reversal of 249686749 is 947686942.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 947686942 = 2 ⋅473843471.

It can be written as a sum of positive squares in 2 ways, for example, as 145033849 + 104652900 = 12043^2 + 10230^2 .

It is a cyclic number.

It is not a de Polignac number, because 249686749 - 2⁷ = 249686621 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 249686749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249686719) 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, 9603324 + ... + 9603349.

It is an arithmetic number, because the mean of its divisors is an integer number (67223359).

Almost surely, 2^249686749 is an apocalyptic number.

It is an amenable number.

249686749 is a deficient number, since it is larger than the sum of its proper divisors (19206687).

249686749 is a wasteful number, since it uses less digits than its factorization.

249686749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19206686.

The product of its digits is 5225472, while the sum is 55.

The square root of 249686749 is about 15801.4793294805. The cubic root of 249686749 is about 629.6973006239.

The spelling of 249686749 in words is "two hundred forty-nine million, six hundred eighty-six thousand, seven hundred forty-nine".