55855440 has 160 divisors (see below), whose sum is σ = 202665600. Its totient is φ = 14100480.

The previous prime is 55855399. The next prime is 55855441. The reversal of 55855440 is 4455855.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 55855395 and 55855404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55855441) 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, 40360 + ... + 41720.

It is an arithmetic number, because the mean of its divisors is an integer number (1266660).

Almost surely, 2^55855440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55855440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101332800).

55855440 is an abundant number, since it is smaller than the sum of its proper divisors (146810160).

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

55855440 is a wasteful number, since it uses less digits than its factorization.

55855440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1402 (or 1390 counting only the distinct ones).

The product of its (nonzero) digits is 80000, while the sum is 36.

The square root of 55855440 is about 7473.6497108173. The cubic root of 55855440 is about 382.2567465259.

It can be divided in two parts, 5585 and 5440, that added together give a square (11025 = 105²).

The spelling of 55855440 in words is "fifty-five million, eight hundred fifty-five thousand, four hundred forty".