20135551 has 16 divisors (see below), whose sum is σ = 21436128. Its totient is φ = 18892800.

The previous prime is 20135539. The next prime is 20135587. The reversal of 20135551 is 15553102.

It is not a de Polignac number, because 20135551 - 2⁹ = 20135039 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 (20135501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 207535 + ... + 207631.

It is an arithmetic number, because the mean of its divisors is an integer number (1339758).

Almost surely, 2^20135551 is an apocalyptic number.

20135551 is a deficient number, since it is larger than the sum of its proper divisors (1300577).

20135551 is an equidigital number, since it uses as much as digits as its factorization.

20135551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282.

The product of its (nonzero) digits is 750, while the sum is 22.

The square root of 20135551 is about 4487.2654256239. The cubic root of 20135551 is about 272.0536181423.

Adding to 20135551 its reverse (15553102), we get a palindrome (35688653).

The spelling of 20135551 in words is "twenty million, one hundred thirty-five thousand, five hundred fifty-one".