262721664 has 128 divisors (see below), whose sum is σ = 816408000. Its totient is φ = 82944000.

The previous prime is 262721659. The next prime is 262721699. The reversal of 262721664 is 466127262.

262721664 is a `hidden beast` number, since 2 + 627 + 21 + 6 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63664 + ... + 67664.

Almost surely, 2^262721664 is an apocalyptic number.

262721664 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 262721664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (408204000).

262721664 is an abundant number, since it is smaller than the sum of its proper divisors (553686336).

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

262721664 is a wasteful number, since it uses less digits than its factorization.

262721664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4043 (or 4025 counting only the distinct ones).

The product of its digits is 48384, while the sum is 36.

The square root of 262721664 is about 16208.6910020520. The cubic root of 262721664 is about 640.4697592795.

The spelling of 262721664 in words is "two hundred sixty-two million, seven hundred twenty-one thousand, six hundred sixty-four".