249581664 has 144 divisors (see below), whose sum is σ = 735566832. Its totient is φ = 80231424.

The previous prime is 249581603. The next prime is 249581677. The reversal of 249581664 is 466185942.

249581664 is a `hidden beast` number, since 2 + 4 + 9 + 581 + 6 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1266814 + ... + 1267010.

It is an arithmetic number, because the mean of its divisors is an integer number (5108103).

Almost surely, 2^249581664 is an apocalyptic number.

249581664 is a gapful number since it is divisible by the number (24) 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 249581664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (367783416).

249581664 is an abundant number, since it is smaller than the sum of its proper divisors (485985168).

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

249581664 is a wasteful number, since it uses less digits than its factorization.

249581664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349 (or 338 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 249581664 is about 15798.1538161900. The cubic root of 249581664 is about 629.6089485501.

The spelling of 249581664 in words is "two hundred forty-nine million, five hundred eighty-one thousand, six hundred sixty-four".