20259391 has 4 divisors (see below), whose sum is σ = 20268792. Its totient is φ = 20249992.

The previous prime is 20259373. The next prime is 20259413. The reversal of 20259391 is 19395202.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20259391 - 2¹⁵ = 20226623 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20259311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321 + ... + 6373.

It is an arithmetic number, because the mean of its divisors is an integer number (5067198).

Almost surely, 2^20259391 is an apocalyptic number.

20259391 is a deficient number, since it is larger than the sum of its proper divisors (9401).

20259391 is an equidigital number, since it uses as much as digits as its factorization.

20259391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9400.

The product of its (nonzero) digits is 4860, while the sum is 31.

The square root of 20259391 is about 4501.0433234973. The cubic root of 20259391 is about 272.6102171773.

The spelling of 20259391 in words is "twenty million, two hundred fifty-nine thousand, three hundred ninety-one".