249561331 has 4 divisors (see below), whose sum is σ = 249863200. Its totient is φ = 249259464.

The previous prime is 249561311. The next prime is 249561349. The reversal of 249561331 is 133165942.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 249561331 - 2¹⁵ = 249528563 is a prime.

It is a super-2 number, since 2×249561331² = 124561715860983122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249561311) 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, 149691 + ... + 151348.

It is an arithmetic number, because the mean of its divisors is an integer number (62465800).

Almost surely, 2^249561331 is an apocalyptic number.

249561331 is a deficient number, since it is larger than the sum of its proper divisors (301869).

249561331 is an equidigital number, since it uses as much as digits as its factorization.

249561331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301868.

The product of its digits is 19440, while the sum is 34.

The square root of 249561331 is about 15797.5102785217. The cubic root of 249561331 is about 629.5918503571.

The spelling of 249561331 in words is "two hundred forty-nine million, five hundred sixty-one thousand, three hundred thirty-one".