20389251 has 4 divisors (see below), whose sum is σ = 27185672. Its totient is φ = 13592832.

The previous prime is 20389249. The next prime is 20389297. The reversal of 20389251 is 15298302.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20389251 - 2¹ = 20389249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20389231) 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, 3398206 + ... + 3398211.

It is an arithmetic number, because the mean of its divisors is an integer number (6796418).

Almost surely, 2^20389251 is an apocalyptic number.

20389251 is a deficient number, since it is larger than the sum of its proper divisors (6796421).

20389251 is an equidigital number, since it uses as much as digits as its factorization.

20389251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6796420.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 20389251 is about 4515.4458251650. The cubic root of 20389251 is about 273.1914421525.

The spelling of 20389251 in words is "twenty million, three hundred eighty-nine thousand, two hundred fifty-one".