264997661 has 4 divisors (see below), whose sum is σ = 265410432. Its totient is φ = 264584892.

The previous prime is 264997619. The next prime is 264997687. The reversal of 264997661 is 166799462.

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: 166799462 = 2 ⋅83399731.

It is a cyclic number.

It is not a de Polignac number, because 264997661 - 2⁶ = 264997597 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 (264997361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205421 + ... + 206706.

It is an arithmetic number, because the mean of its divisors is an integer number (66352608).

Almost surely, 2^264997661 is an apocalyptic number.

It is an amenable number.

264997661 is a deficient number, since it is larger than the sum of its proper divisors (412771).

264997661 is an equidigital number, since it uses as much as digits as its factorization.

264997661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412770.

The product of its digits is 979776, while the sum is 50.

The square root of 264997661 is about 16278.7487541273. The cubic root of 264997661 is about 642.3139390686.

The spelling of 264997661 in words is "two hundred sixty-four million, nine hundred ninety-seven thousand, six hundred sixty-one".