249399640 has 64 divisors (see below), whose sum is σ = 642816000. Its totient is φ = 85308288.

The previous prime is 249399629. The next prime is 249399653. The reversal of 249399640 is 46993942.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166977 + ... + 168463.

It is an arithmetic number, because the mean of its divisors is an integer number (10044000).

Almost surely, 2^249399640 is an apocalyptic number.

249399640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 249399640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321408000).

249399640 is an abundant number, since it is smaller than the sum of its proper divisors (393416360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

249399640 is a wasteful number, since it uses less digits than its factorization.

249399640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2104 (or 2100 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 46.

The square root of 249399640 is about 15792.3918391104. The cubic root of 249399640 is about 629.4558499483.

The spelling of 249399640 in words is "two hundred forty-nine million, three hundred ninety-nine thousand, six hundred forty".