20091391 has 2 divisors, whose sum is σ = 20091392. Its totient is φ = 20091390.

The previous prime is 20091389. The next prime is 20091413. The reversal of 20091391 is 19319002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20091391 - 2¹ = 20091389 is a prime.

Together with 20091389, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20091311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10045695 + 10045696.

It is an arithmetic number, because the mean of its divisors is an integer number (10045696).

Almost surely, 2^20091391 is an apocalyptic number.

20091391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20091391 is an equidigital number, since it uses as much as digits as its factorization.

20091391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 20091391 is about 4482.3421333049. The cubic root of 20091391 is about 271.8545890521.

The spelling of 20091391 in words is "twenty million, ninety-one thousand, three hundred ninety-one".