252661421 has 4 divisors (see below), whose sum is σ = 258537312. Its totient is φ = 246785532.

The previous prime is 252661399. The next prime is 252661433. The reversal of 252661421 is 124166252.

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.

It is a cyclic number.

It is not a de Polignac number, because 252661421 - 2²⁶ = 185552557 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 (252661471) 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, 2937881 + ... + 2937966.

It is an arithmetic number, because the mean of its divisors is an integer number (64634328).

Almost surely, 2^252661421 is an apocalyptic number.

It is an amenable number.

252661421 is a deficient number, since it is larger than the sum of its proper divisors (5875891).

252661421 is an equidigital number, since it uses as much as digits as its factorization.

252661421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5875890.

The product of its digits is 5760, while the sum is 29.

The square root of 252661421 is about 15895.3270177118. The cubic root of 252661421 is about 632.1880924491.

The spelling of 252661421 in words is "two hundred fifty-two million, six hundred sixty-one thousand, four hundred twenty-one".