244891991 has 2 divisors, whose sum is σ = 244891992. Its totient is φ = 244891990.

The previous prime is 244891981. The next prime is 244892023. The reversal of 244891991 is 199198442.

244891991 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 a de Polignac number, because none of the positive numbers 2^k-244891991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (244891961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122445995 + 122445996.

It is an arithmetic number, because the mean of its divisors is an integer number (122445996).

Almost surely, 2^244891991 is an apocalyptic number.

244891991 is a deficient number, since it is larger than the sum of its proper divisors (1).

244891991 is an equidigital number, since it uses as much as digits as its factorization.

244891991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 47.

The square root of 244891991 is about 15649.0252412091. The cubic root of 244891991 is about 625.6405090262.

The spelling of 244891991 in words is "two hundred forty-four million, eight hundred ninety-one thousand, nine hundred ninety-one".