249399805 has 32 divisors (see below), whose sum is σ = 317260800. Its totient is φ = 187968000.

The previous prime is 249399803. The next prime is 249399823. The reversal of 249399805 is 508993942.

It is not a de Polignac number, because 249399805 - 2¹ = 249399803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249399803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1393206 + ... + 1393384.

It is an arithmetic number, because the mean of its divisors is an integer number (9914400).

Almost surely, 2^249399805 is an apocalyptic number.

It is an amenable number.

249399805 is a deficient number, since it is larger than the sum of its proper divisors (67860995).

249399805 is a wasteful number, since it uses less digits than its factorization.

249399805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405.

The product of its (nonzero) digits is 699840, while the sum is 49.

The square root of 249399805 is about 15792.3970631440. The cubic root of 249399805 is about 629.4559887619.

The spelling of 249399805 in words is "two hundred forty-nine million, three hundred ninety-nine thousand, eight hundred five".