20123251 has 6 divisors (see below), whose sum is σ = 20627756. Its totient is φ = 19630800.

The previous prime is 20123239. The next prime is 20123263. The reversal of 20123251 is 15232102.

It is an interprime number because it is at equal distance from previous prime (20123239) and next prime (20123263).

It is not a de Polignac number, because 20123251 - 2²³ = 11734643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20123231) 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 5 ways as a sum of consecutive naturals, for example, 4305 + ... + 7666.

Almost surely, 2^20123251 is an apocalyptic number.

20123251 is a deficient number, since it is larger than the sum of its proper divisors (504505).

20123251 is an equidigital number, since it uses as much as digits as its factorization.

20123251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12053 (or 12012 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 20123251 is about 4485.8946710773. The cubic root of 20123251 is about 271.9982113132.

Adding to 20123251 its reverse (15232102), we get a palindrome (35355353).

The spelling of 20123251 in words is "twenty million, one hundred twenty-three thousand, two hundred fifty-one".