264405509 has 4 divisors (see below), whose sum is σ = 264438240. Its totient is φ = 264372780.

The previous prime is 264405487. The next prime is 264405511. The reversal of 264405509 is 905504462.

It is a happy number.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 905504462 = 2 ⋅452752231.

It is a cyclic number.

It is not a de Polignac number, because 264405509 - 2¹² = 264401413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264405569) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 5414 + ... + 23624.

It is an arithmetic number, because the mean of its divisors is an integer number (66109560).

Almost surely, 2^264405509 is an apocalyptic number.

It is an amenable number.

264405509 is a deficient number, since it is larger than the sum of its proper divisors (32731).

264405509 is a wasteful number, since it uses less digits than its factorization.

264405509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32730.

The product of its (nonzero) digits is 43200, while the sum is 35.

The square root of 264405509 is about 16260.5506979315. The cubic root of 264405509 is about 641.8351535365.

The spelling of 264405509 in words is "two hundred sixty-four million, four hundred five thousand, five hundred nine".