242021891 has 2 divisors, whose sum is σ = 242021892. Its totient is φ = 242021890.

The previous prime is 242021873. The next prime is 242021933. The reversal of 242021891 is 198120242.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 242021891 - 2²² = 237827587 is a prime.

It is not a weakly prime, because it can be changed into another prime (242021821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121010945 + 121010946.

It is an arithmetic number, because the mean of its divisors is an integer number (121010946).

Almost surely, 2^242021891 is an apocalyptic number.

242021891 is a deficient number, since it is larger than the sum of its proper divisors (1).

242021891 is an equidigital number, since it uses as much as digits as its factorization.

242021891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 242021891 is about 15557.0527735815. The cubic root of 242021891 is about 623.1867581872.

The spelling of 242021891 in words is "two hundred forty-two million, twenty-one thousand, eight hundred ninety-one".