20238391 has 2 divisors, whose sum is σ = 20238392. Its totient is φ = 20238390.

The previous prime is 20238373. The next prime is 20238403. The reversal of 20238391 is 19383202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20238391 - 2¹⁵ = 20205623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20238191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10119195 + 10119196.

It is an arithmetic number, because the mean of its divisors is an integer number (10119196).

Almost surely, 2^20238391 is an apocalyptic number.

20238391 is a deficient number, since it is larger than the sum of its proper divisors (1).

20238391 is an equidigital number, since it uses as much as digits as its factorization.

20238391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20238391 is about 4498.7099261900. The cubic root of 20238391 is about 272.5159926646.

The spelling of 20238391 in words is "twenty million, two hundred thirty-eight thousand, three hundred ninety-one".