565121664 has 128 divisors (see below), whose sum is σ = 1685448000. Its totient is φ = 186393600.

The previous prime is 565121653. The next prime is 565121717. The reversal of 565121664 is 466121565.

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, 348247 + ... + 349865.

Almost surely, 2^565121664 is an apocalyptic number.

565121664 is a gapful number since it is divisible by the number (54) 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 565121664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (842724000).

565121664 is an abundant number, since it is smaller than the sum of its proper divisors (1120326336).

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

565121664 is a wasteful number, since it uses less digits than its factorization.

565121664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1743 (or 1725 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 565121664 is about 23772.2877317266. The cubic root of 565121664 is about 826.7622759113.

Subtracting from 565121664 its reverse (466121565), we obtain a palindrome (99000099).

The spelling of 565121664 in words is "five hundred sixty-five million, one hundred twenty-one thousand, six hundred sixty-four".