20012251 has 4 divisors (see below), whose sum is σ = 22871152. Its totient is φ = 17153352.

The previous prime is 20012219. The next prime is 20012261. The reversal of 20012251 is 15221002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15221002 = 2 ⋅7610501.

It is a cyclic number.

It is not a de Polignac number, because 20012251 - 2⁵ = 20012219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20012261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1429440 + ... + 1429453.

It is an arithmetic number, because the mean of its divisors is an integer number (5717788).

Almost surely, 2^20012251 is an apocalyptic number.

20012251 is a deficient number, since it is larger than the sum of its proper divisors (2858901).

20012251 is an equidigital number, since it uses as much as digits as its factorization.

20012251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2858900.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 20012251 is about 4473.5054487505. The cubic root of 20012251 is about 271.4971742304.

Adding to 20012251 its reverse (15221002), we get a palindrome (35233253).

The spelling of 20012251 in words is "twenty million, twelve thousand, two hundred fifty-one".