249355681 has 3 divisors (see below), whose sum is σ = 249371473. Its totient is φ = 249339890.

The previous prime is 249355651. The next prime is 249355693. The reversal of 249355681 is 186553942.

The square root of 249355681 is 15791.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 249355681 - 2⁵ = 249355649 is a prime.

It is a super-2 number, since 2×249355681² = 124356511293947522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249355651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7896 + ... + 23686.

Almost surely, 2^249355681 is an apocalyptic number.

249355681 is the 15791-st square number.

249355681 is the 7896-th centered octagonal number.

It is an amenable number.

249355681 is a deficient number, since it is larger than the sum of its proper divisors (15792).

249355681 is an frugal number, since it uses more digits than its factorization.

249355681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31582 (or 15791 counting only the distinct ones).

The product of its digits is 259200, while the sum is 43.

The cubic root of 249355681 is about 629.4188652978.

The spelling of 249355681 in words is "two hundred forty-nine million, three hundred fifty-five thousand, six hundred eighty-one".