24397991 has 2 divisors, whose sum is σ = 24397992. Its totient is φ = 24397990.

The previous prime is 24397981. The next prime is 24398021. The reversal of 24397991 is 19979342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 24397991 - 2⁶ = 24397927 is a prime.

It is a Sophie Germain 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 (24397921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12198995 + 12198996.

It is an arithmetic number, because the mean of its divisors is an integer number (12198996).

Almost surely, 2^24397991 is an apocalyptic number.

24397991 is a deficient number, since it is larger than the sum of its proper divisors (1).

24397991 is an equidigital number, since it uses as much as digits as its factorization.

24397991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 122472, while the sum is 44.

The square root of 24397991 is about 4939.4322548244. The cubic root of 24397991 is about 290.0356317693.

The spelling of 24397991 in words is "twenty-four million, three hundred ninety-seven thousand, nine hundred ninety-one".