221953867 has 2 divisors, whose sum is σ = 221953868. Its totient is φ = 221953866.

The previous prime is 221953817. The next prime is 221953871. The reversal of 221953867 is 768359122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221953867 - 2¹⁵ = 221921099 is a prime.

It is not a weakly prime, because it can be changed into another prime (221953817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110976933 + 110976934.

It is an arithmetic number, because the mean of its divisors is an integer number (110976934).

Almost surely, 2^221953867 is an apocalyptic number.

221953867 is a deficient number, since it is larger than the sum of its proper divisors (1).

221953867 is an equidigital number, since it uses as much as digits as its factorization.

221953867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 43.

The square root of 221953867 is about 14898.1162232008. The cubic root of 221953867 is about 605.4629491669.

It can be divided in two parts, 22195 and 3867, that added together give a palindrome (26062).

The spelling of 221953867 in words is "two hundred twenty-one million, nine hundred fifty-three thousand, eight hundred sixty-seven".