55531566 has 48 divisors (see below), whose sum is σ = 127280400. Its totient is φ = 17449344.

The previous prime is 55531529. The next prime is 55531577. The reversal of 55531566 is 66513555.

It is a self number, because there is not a number n which added to its sum of digits gives 55531566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135570 + ... + 135978.

It is an arithmetic number, because the mean of its divisors is an integer number (2651675).

Almost surely, 2^55531566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55531566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63640200).

55531566 is an abundant number, since it is smaller than the sum of its proper divisors (71748834).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55531566 is a wasteful number, since it uses less digits than its factorization.

55531566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 833 (or 830 counting only the distinct ones).

The product of its digits is 67500, while the sum is 36.

The square root of 55531566 is about 7451.9504829273. The cubic root of 55531566 is about 381.5164839053.

The spelling of 55531566 in words is "fifty-five million, five hundred thirty-one thousand, five hundred sixty-six".