2371991 has 2 divisors, whose sum is σ = 2371992. Its totient is φ = 2371990.

The previous prime is 2371969. The next prime is 2372011. The reversal of 2371991 is 1991732.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2371991 - 2⁶ = 2371927 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2371961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1185995 + 1185996.

It is an arithmetic number, because the mean of its divisors is an integer number (1185996).

2^2371991 is an apocalyptic number.

2371991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2371991 is an equidigital number, since it uses as much as digits as its factorization.

2371991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3402, while the sum is 32.

The square root of 2371991 is about 1540.1269428200. The cubic root of 2371991 is about 133.3637132163.

The spelling of 2371991 in words is "two million, three hundred seventy-one thousand, nine hundred ninety-one".