20106551 has 4 divisors (see below), whose sum is σ = 20447400. Its totient is φ = 19765704.

The previous prime is 20106521. The next prime is 20106589. The reversal of 20106551 is 15560102.

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 20106551 - 2⁶ = 20106487 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 (20106521) 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, 170336 + ... + 170453.

It is an arithmetic number, because the mean of its divisors is an integer number (5111850).

Almost surely, 2^20106551 is an apocalyptic number.

20106551 is a deficient number, since it is larger than the sum of its proper divisors (340849).

20106551 is an equidigital number, since it uses as much as digits as its factorization.

20106551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340848.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 20106551 is about 4484.0328946162. The cubic root of 20106551 is about 271.9229480061.

Adding to 20106551 its reverse (15560102), we get a palindrome (35666653).

The spelling of 20106551 in words is "twenty million, one hundred six thousand, five hundred fifty-one".