249987720 has 256 divisors, whose sum is σ = 846028800. Its totient is φ = 58798080.

The previous prime is 249987677. The next prime is 249987733. The reversal of 249987720 is 27789942.

It is a Cunningham number, because it is equal to 15811²-1.

It is a self number, because there is not a number n which added to its sum of digits gives 249987720.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3731127 + ... + 3731193.

It is an arithmetic number, because the mean of its divisors is an integer number (3304800).

Almost surely, 2^249987720 is an apocalyptic number.

249987720 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 249987720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (423014400).

249987720 is an abundant number, since it is smaller than the sum of its proper divisors (596041080).

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

249987720 is a wasteful number, since it uses less digits than its factorization.

249987720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 48.

The square root of 249987720 is about 15810.9999683764. Note that the first 4 decimals coincide. The cubic root of 249987720 is about 629.9502102249.

The spelling of 249987720 in words is "two hundred forty-nine million, nine hundred eighty-seven thousand, seven hundred twenty".