55511511 has 32 divisors (see below), whose sum is σ = 87153408. Its totient is φ = 31050240.

The previous prime is 55511509. The next prime is 55511537. The reversal of 55511511 is 11511555.

It is not a de Polignac number, because 55511511 - 2¹ = 55511509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55511501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28800 + ... + 30666.

It is an arithmetic number, because the mean of its divisors is an integer number (2723544).

Almost surely, 2^55511511 is an apocalyptic number.

55511511 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

55511511 is a deficient number, since it is larger than the sum of its proper divisors (31641897).

55511511 is a wasteful number, since it uses less digits than its factorization.

55511511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1951.

The product of its digits is 625, while the sum is 24.

The square root of 55511511 is about 7450.6047405563. The cubic root of 55511511 is about 381.4705506647.

It can be divided in two parts, 55 and 511511, that added together give a triangular number (511566 = T₁₀₁₁).

The spelling of 55511511 in words is "fifty-five million, five hundred eleven thousand, five hundred eleven".