55585551 has 20 divisors (see below), whose sum is σ = 86472472. Its totient is φ = 31759056.

The previous prime is 55585513. The next prime is 55585561. The reversal of 55585551 is 15558555.

It is not a de Polignac number, because 55585551 - 2¹⁰ = 55584527 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 (55585501) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3345 + ... + 11061.

Almost surely, 2^55585551 is an apocalyptic number.

55585551 is a deficient number, since it is larger than the sum of its proper divisors (30886921).

55585551 is an frugal number, since it uses more digits than its factorization.

55585551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7748 (or 7727 counting only the distinct ones).

The product of its digits is 125000, while the sum is 39.

The square root of 55585551 is about 7455.5718090566. The cubic root of 55585551 is about 381.6400742539.

The spelling of 55585551 in words is "fifty-five million, five hundred eighty-five thousand, five hundred fifty-one".