221231429 has 2 divisors, whose sum is σ = 221231430. Its totient is φ = 221231428.

The previous prime is 221231393. The next prime is 221231467. The reversal of 221231429 is 924132122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191822500 + 29408929 = 13850^2 + 5423^2 .

It is a cyclic number.

It is not a de Polignac number, because 221231429 - 2²⁴ = 204454213 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221231398 and 221231407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221231629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110615714 + 110615715.

It is an arithmetic number, because the mean of its divisors is an integer number (110615715).

Almost surely, 2^221231429 is an apocalyptic number.

It is an amenable number.

221231429 is a deficient number, since it is larger than the sum of its proper divisors (1).

221231429 is an equidigital number, since it uses as much as digits as its factorization.

221231429 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 26.

The square root of 221231429 is about 14873.8505102075. The cubic root of 221231429 is about 604.8053277087.

The spelling of 221231429 in words is "two hundred twenty-one million, two hundred thirty-one thousand, four hundred twenty-nine".