55115551 has 16 divisors (see below), whose sum is σ = 58798080. Its totient is φ = 51579360.

The previous prime is 55115549. The next prime is 55115591. The reversal of 55115551 is 15551155.

It is not a de Polignac number, because 55115551 - 2¹ = 55115549 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 (55115531) 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, 230490 + ... + 230728.

It is an arithmetic number, because the mean of its divisors is an integer number (3674880).

Almost surely, 2^55115551 is an apocalyptic number.

55115551 is a deficient number, since it is larger than the sum of its proper divisors (3682529).

55115551 is a wasteful number, since it uses less digits than its factorization.

55115551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486.

The product of its digits is 3125, while the sum is 28.

The square root of 55115551 is about 7423.9848464285. The cubic root of 55115551 is about 380.5613840023.

The spelling of 55115551 in words is "fifty-five million, one hundred fifteen thousand, five hundred fifty-one".