221429837 has 2 divisors, whose sum is σ = 221429838. Its totient is φ = 221429836.

The previous prime is 221429827. The next prime is 221429839. The reversal of 221429837 is 738924122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 178997641 + 42432196 = 13379^2 + 6514^2 .

It is a cyclic number.

It is not a de Polignac number, because 221429837 - 2⁴ = 221429821 is a prime.

Together with 221429839, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221429837.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221429839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110714918 + 110714919.

It is an arithmetic number, because the mean of its divisors is an integer number (110714919).

Almost surely, 2^221429837 is an apocalyptic number.

It is an amenable number.

221429837 is a deficient number, since it is larger than the sum of its proper divisors (1).

221429837 is an equidigital number, since it uses as much as digits as its factorization.

221429837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 38.

The square root of 221429837 is about 14880.5187073569. The cubic root of 221429837 is about 604.9860771333.

The spelling of 221429837 in words is "two hundred twenty-one million, four hundred twenty-nine thousand, eight hundred thirty-seven".