20159251 has 4 divisors (see below), whose sum is σ = 23039152. Its totient is φ = 17279352.

The previous prime is 20159203. The next prime is 20159261. The reversal of 20159251 is 15295102.

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

It is a cyclic number.

It is not a de Polignac number, because 20159251 - 2⁹ = 20158739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20159261) 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, 1439940 + ... + 1439953.

It is an arithmetic number, because the mean of its divisors is an integer number (5759788).

Almost surely, 2^20159251 is an apocalyptic number.

20159251 is a deficient number, since it is larger than the sum of its proper divisors (2879901).

20159251 is an equidigital number, since it uses as much as digits as its factorization.

20159251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2879900.

The product of its (nonzero) digits is 900, while the sum is 25.

The square root of 20159251 is about 4489.9054555748. The cubic root of 20159251 is about 272.1603140508.

The spelling of 20159251 in words is "twenty million, one hundred fifty-nine thousand, two hundred fifty-one".