249717731328 has 624 divisors, whose sum is σ = 828861050880. Its totient is φ = 74185113600.

The previous prime is 249717731317. The next prime is 249717731357. The reversal of 249717731328 is 823137717942.

249717731328 is a `hidden beast` number, since 2 + 497 + 17 + 7 + 3 + 132 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (624).

It is a super-3 number, since 3×249717731328³ (a number of 35 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 579391273 + ... + 579391703.

Almost surely, 2^249717731328 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 249717731328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (414430525440).

249717731328 is an abundant number, since it is smaller than the sum of its proper divisors (579143319552).

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

249717731328 is a wasteful number, since it uses less digits than its factorization.

249717731328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 480 counting only the distinct ones).

The product of its digits is 3556224, while the sum is 54.

The spelling of 249717731328 in words is "two hundred forty-nine billion, seven hundred seventeen million, seven hundred thirty-one thousand, three hundred twenty-eight".