221657229 has 20 divisors (see below), whose sum is σ = 332108700. Its totient is φ = 147329280.

The previous prime is 221657221. The next prime is 221657251. The reversal of 221657229 is 922756122.

It is a happy number.

221657229 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 120956004 + 100701225 = 10998^2 + 10035^2 .

It is not a de Polignac number, because 221657229 - 2³ = 221657221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221657193 and 221657202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221657221) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24349 + ... + 32189.

It is an arithmetic number, because the mean of its divisors is an integer number (16605435).

Almost surely, 2^221657229 is an apocalyptic number.

It is an amenable number.

221657229 is a deficient number, since it is larger than the sum of its proper divisors (110451471).

221657229 is an equidigital number, since it uses as much as digits as its factorization.

221657229 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8202 (or 8193 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 221657229 is about 14888.1573406517. The cubic root of 221657229 is about 605.1930982101.

The spelling of 221657229 in words is "two hundred twenty-one million, six hundred fifty-seven thousand, two hundred twenty-nine".