229121921 has 4 divisors (see below), whose sum is σ = 261853632. Its totient is φ = 196390212.

The previous prime is 229121911. The next prime is 229121933. The reversal of 229121921 is 129121922.

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: 129121922 = 2 ⋅64560961.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-229121921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (229121911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16365845 + ... + 16365858.

It is an arithmetic number, because the mean of its divisors is an integer number (65463408).

Almost surely, 2^229121921 is an apocalyptic number.

It is an amenable number.

229121921 is a deficient number, since it is larger than the sum of its proper divisors (32731711).

229121921 is an equidigital number, since it uses as much as digits as its factorization.

229121921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32731710.

The product of its digits is 1296, while the sum is 29.

The square root of 229121921 is about 15136.7737976096. The cubic root of 229121921 is about 611.9118739427.

Subtracting from 229121921 its reverse (129121922), we obtain a palindrome (99999999).

The spelling of 229121921 in words is "two hundred twenty-nine million, one hundred twenty-one thousand, nine hundred twenty-one".