264021421 has 4 divisors (see below), whose sum is σ = 264922812. Its totient is φ = 263120032.

The previous prime is 264021403. The next prime is 264021431. The reversal of 264021421 is 124120462.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 190302025 + 73719396 = 13795^2 + 8586^2 .

It is a cyclic number.

It is not a de Polignac number, because 264021421 - 2¹⁷ = 263890349 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 264021392 and 264021401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (264021431) 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, 450256 + ... + 450841.

It is an arithmetic number, because the mean of its divisors is an integer number (66230703).

Almost surely, 2^264021421 is an apocalyptic number.

It is an amenable number.

264021421 is a deficient number, since it is larger than the sum of its proper divisors (901391).

264021421 is an equidigital number, since it uses as much as digits as its factorization.

264021421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901390.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 264021421 is about 16248.7359816079. The cubic root of 264021421 is about 641.5242161847.

Adding to 264021421 its reverse (124120462), we get a palindrome (388141883).

The spelling of 264021421 in words is "two hundred sixty-four million, twenty-one thousand, four hundred twenty-one".