20125551 has 4 divisors (see below), whose sum is σ = 26834072. Its totient is φ = 13417032.

The previous prime is 20125543. The next prime is 20125583. The reversal of 20125551 is 15552102.

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

It is not a de Polignac number, because 20125551 - 2³ = 20125543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20125051) 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, 3354256 + ... + 3354261.

It is an arithmetic number, because the mean of its divisors is an integer number (6708518).

Almost surely, 2^20125551 is an apocalyptic number.

20125551 is a deficient number, since it is larger than the sum of its proper divisors (6708521).

20125551 is an equidigital number, since it uses as much as digits as its factorization.

20125551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6708520.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 20125551 is about 4486.1510228703. The cubic root of 20125551 is about 272.0085736556.

Adding to 20125551 its reverse (15552102), we get a palindrome (35677653).

It can be divided in two parts, 201 and 25551, that added together give a palindrome (25752).

The spelling of 20125551 in words is "twenty million, one hundred twenty-five thousand, five hundred fifty-one".