2401991 has 2 divisors, whose sum is σ = 2401992. Its totient is φ = 2401990.

The previous prime is 2401969. The next prime is 2402009. The reversal of 2401991 is 1991042.

2401991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2401991 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2401991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2401891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1200995 + 1200996.

It is an arithmetic number, because the mean of its divisors is an integer number (1200996).

2^2401991 is an apocalyptic number.

2401991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2401991 is an equidigital number, since it uses as much as digits as its factorization.

2401991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 2401991 is about 1549.8357977541. The cubic root of 2401991 is about 133.9236031444.

The spelling of 2401991 in words is "two million, four hundred one thousand, nine hundred ninety-one".