264921521 has 4 divisors (see below), whose sum is σ = 276439872. Its totient is φ = 253403172.

The previous prime is 264921509. The next prime is 264921571. The reversal of 264921521 is 125129462.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125129462 = 2 ⋅62564731.

It is a cyclic number.

It is not a de Polignac number, because 264921521 - 2¹⁰ = 264920497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (264921571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5759141 + ... + 5759186.

It is an arithmetic number, because the mean of its divisors is an integer number (69109968).

Almost surely, 2^264921521 is an apocalyptic number.

It is an amenable number.

264921521 is a deficient number, since it is larger than the sum of its proper divisors (11518351).

264921521 is a wasteful number, since it uses less digits than its factorization.

264921521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11518350.

The product of its digits is 8640, while the sum is 32.

The square root of 264921521 is about 16276.4099542866. The cubic root of 264921521 is about 642.2524159244.

The spelling of 264921521 in words is "two hundred sixty-four million, nine hundred twenty-one thousand, five hundred twenty-one".