249643645 has 4 divisors (see below), whose sum is σ = 299572380. Its totient is φ = 199714912.

The previous prime is 249643627. The next prime is 249643673. The reversal of 249643645 is 546346942.

It is a happy number.

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 186568281 + 63075364 = 13659^2 + 7942^2 .

It is a cyclic number.

It is not a de Polignac number, because 249643645 - 2⁷ = 249643517 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24964360 + ... + 24964369.

It is an arithmetic number, because the mean of its divisors is an integer number (74893095).

Almost surely, 2^249643645 is an apocalyptic number.

It is an amenable number.

249643645 is a deficient number, since it is larger than the sum of its proper divisors (49928735).

249643645 is an equidigital number, since it uses as much as digits as its factorization.

249643645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49928734.

The product of its digits is 622080, while the sum is 43.

The square root of 249643645 is about 15800.1153476802. The cubic root of 249643645 is about 629.6610631722.

The spelling of 249643645 in words is "two hundred forty-nine million, six hundred forty-three thousand, six hundred forty-five".