221331629 has 2 divisors, whose sum is σ = 221331630. Its totient is φ = 221331628.

The previous prime is 221331623. The next prime is 221331641. The reversal of 221331629 is 926133122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118309129 + 103022500 = 10877^2 + 10150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221331629 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221331623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110665814 + 110665815.

It is an arithmetic number, because the mean of its divisors is an integer number (110665815).

Almost surely, 2^221331629 is an apocalyptic number.

It is an amenable number.

221331629 is a deficient number, since it is larger than the sum of its proper divisors (1).

221331629 is an equidigital number, since it uses as much as digits as its factorization.

221331629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 29.

The square root of 221331629 is about 14877.2184564185. The cubic root of 221331629 is about 604.8966232768.

The spelling of 221331629 in words is "two hundred twenty-one million, three hundred thirty-one thousand, six hundred twenty-nine".