264398021 has 4 divisors (see below), whose sum is σ = 264781344. Its totient is φ = 264014700.

The previous prime is 264398009. The next prime is 264398033. The reversal of 264398021 is 120893462.

264398021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 120893462 = 2 ⋅60446731.

It is an interprime number because it is at equal distance from previous prime (264398009) and next prime (264398033).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-264398021 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 (264398621) 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, 190625 + ... + 192006.

It is an arithmetic number, because the mean of its divisors is an integer number (66195336).

Almost surely, 2^264398021 is an apocalyptic number.

It is an amenable number.

264398021 is a deficient number, since it is larger than the sum of its proper divisors (383323).

264398021 is an equidigital number, since it uses as much as digits as its factorization.

264398021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383322.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 264398021 is about 16260.3204457969. The cubic root of 264398021 is about 641.8290945263.

The spelling of 264398021 in words is "two hundred sixty-four million, three hundred ninety-eight thousand, twenty-one".