55405520 has 40 divisors (see below), whose sum is σ = 135601440. Its totient is φ = 20995200.

The previous prime is 55405517. The next prime is 55405541. The reversal of 55405520 is 2550455.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 55405520.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16706 + ... + 19745.

It is an arithmetic number, because the mean of its divisors is an integer number (3390036).

Almost surely, 2^55405520 is an apocalyptic number.

It is an amenable number.

55405520 is an abundant number, since it is smaller than the sum of its proper divisors (80195920).

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

55405520 is a wasteful number, since it uses less digits than its factorization.

55405520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36483 (or 36477 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 26.

The square root of 55405520 is about 7443.4884294933. The cubic root of 55405520 is about 381.2276088256.

Adding to 55405520 its reverse (2550455), we get a palindrome (57955975).

The spelling of 55405520 in words is "fifty-five million, four hundred five thousand, five hundred twenty".