221938291 has 2 divisors, whose sum is σ = 221938292. Its totient is φ = 221938290.

The previous prime is 221938273. The next prime is 221938319. The reversal of 221938291 is 192839122.

221938291 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221938291 - 2⁷ = 221938163 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221938291.

It is not a weakly prime, because it can be changed into another prime (221938271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110969145 + 110969146.

It is an arithmetic number, because the mean of its divisors is an integer number (110969146).

Almost surely, 2^221938291 is an apocalyptic number.

221938291 is a deficient number, since it is larger than the sum of its proper divisors (1).

221938291 is an equidigital number, since it uses as much as digits as its factorization.

221938291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 37.

The square root of 221938291 is about 14897.5934633752. The cubic root of 221938291 is about 605.4487856959.

The spelling of 221938291 in words is "two hundred twenty-one million, nine hundred thirty-eight thousand, two hundred ninety-one".