221572829 has 2 divisors, whose sum is σ = 221572830. Its totient is φ = 221572828.

The previous prime is 221572763. The next prime is 221572831. The reversal of 221572829 is 928275122.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 221563225 + 9604 = 14885^2 + 98^2 .

It is a cyclic number.

It is not a de Polignac number, because 221572829 - 2⁸ = 221572573 is a prime.

Together with 221572831, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 221572792 and 221572801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221572859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110786414 + 110786415.

It is an arithmetic number, because the mean of its divisors is an integer number (110786415).

Almost surely, 2^221572829 is an apocalyptic number.

It is an amenable number.

221572829 is a deficient number, since it is larger than the sum of its proper divisors (1).

221572829 is an equidigital number, since it uses as much as digits as its factorization.

221572829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 38.

The square root of 221572829 is about 14885.3226031551. The cubic root of 221572829 is about 605.1162757185.

The spelling of 221572829 in words is "two hundred twenty-one million, five hundred seventy-two thousand, eight hundred twenty-nine".