20228251 has 4 divisors (see below), whose sum is σ = 20293192. Its totient is φ = 20163312.

The previous prime is 20228239. The next prime is 20228267. The reversal of 20228251 is 15282202.

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 20228251 - 2²³ = 11839643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20228281) 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, 32001 + ... + 32626.

It is an arithmetic number, because the mean of its divisors is an integer number (5073298).

Almost surely, 2^20228251 is an apocalyptic number.

20228251 is a deficient number, since it is larger than the sum of its proper divisors (64941).

20228251 is an equidigital number, since it uses as much as digits as its factorization.

20228251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64940.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 20228251 is about 4497.5827952357. The cubic root of 20228251 is about 272.4704723497.

The spelling of 20228251 in words is "twenty million, two hundred twenty-eight thousand, two hundred fifty-one".