55817680 has 40 divisors (see below), whose sum is σ = 131132232. Its totient is φ = 22093824.

The previous prime is 55817669. The next prime is 55817683. The reversal of 55817680 is 8671855.

It can be written as a sum of positive squares in 4 ways, for example, as 46656 + 55771024 = 216^2 + 7468^2 .

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

It is a super-2 number, since 2×55817680² = 6231226801164800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55817683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4164 + ... + 11356.

Almost surely, 2^55817680 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 55817680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65566116).

55817680 is an abundant number, since it is smaller than the sum of its proper divisors (75314552).

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

55817680 is a wasteful number, since it uses less digits than its factorization.

55817680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7303 (or 7297 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 55817680 is about 7471.1230748797. The cubic root of 55817680 is about 382.1705879913.

The spelling of 55817680 in words is "fifty-five million, eight hundred seventeen thousand, six hundred eighty".