249721560 has 192 divisors, whose sum is σ = 932256000. Its totient is φ = 57335040.

The previous prime is 249721513. The next prime is 249721573. The reversal of 249721560 is 65127942.

249721560 is a `hidden beast` number, since 2 + 4 + 97 + 2 + 1 + 560 = 666.

249721560 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73581 + ... + 76899.

It is an arithmetic number, because the mean of its divisors is an integer number (4855500).

Almost surely, 2^249721560 is an apocalyptic number.

249721560 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 249721560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (466128000).

249721560 is an abundant number, since it is smaller than the sum of its proper divisors (682534440).

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

249721560 is a wasteful number, since it uses less digits than its factorization.

249721560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3366 (or 3359 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 249721560 is about 15802.5808018817. The cubic root of 249721560 is about 629.7265631221.

The spelling of 249721560 in words is "two hundred forty-nine million, seven hundred twenty-one thousand, five hundred sixty".