55805640 has 128 divisors (see below), whose sum is σ = 185656320. Its totient is φ = 13305600.

The previous prime is 55805639. The next prime is 55805663. The reversal of 55805640 is 4650855.

It is a super-2 number, since 2×55805640² = 6228538911619200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 88125 + ... + 88755.

It is an arithmetic number, because the mean of its divisors is an integer number (1450440).

Almost surely, 2^55805640 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 55805640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92828160).

55805640 is an abundant number, since it is smaller than the sum of its proper divisors (129850680).

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

55805640 is a wasteful number, since it uses less digits than its factorization.

55805640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723 (or 719 counting only the distinct ones).

The product of its (nonzero) digits is 24000, while the sum is 33.

The square root of 55805640 is about 7470.3172623390. The cubic root of 55805640 is about 382.1431076616.

It can be divided in two parts, 558056 and 40, that added together give a triangular number (558096 = T₁₀₅₆).

The spelling of 55805640 in words is "fifty-five million, eight hundred five thousand, six hundred forty".