442123991 has 2 divisors, whose sum is σ = 442123992. Its totient is φ = 442123990.

The previous prime is 442123973. The next prime is 442123999. The reversal of 442123991 is 199321244.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-442123991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442123999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221061995 + 221061996.

It is an arithmetic number, because the mean of its divisors is an integer number (221061996).

Almost surely, 2^442123991 is an apocalyptic number.

442123991 is a deficient number, since it is larger than the sum of its proper divisors (1).

442123991 is an equidigital number, since it uses as much as digits as its factorization.

442123991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 35.

The square root of 442123991 is about 21026.7446600752. The cubic root of 442123991 is about 761.8123821931.

The spelling of 442123991 in words is "four hundred forty-two million, one hundred twenty-three thousand, nine hundred ninety-one".