61800 has 48 divisors (see below), whose sum is σ = 193440. Its totient is φ = 16320.

The previous prime is 61781. The next prime is 61813. The reversal of 61800 is 816.

61800 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 61800.

It is an unprimeable number.

61800 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 549 + ... + 651.

It is an arithmetic number, because the mean of its divisors is an integer number (4030).

2⁶¹⁸⁰⁰ is an apocalyptic number.

61800 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96720).

61800 is an abundant number, since it is smaller than the sum of its proper divisors (131640).

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

61800 is a wasteful number, since it uses less digits than its factorization.

61800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 61800 is about 248.5960578931. The cubic root of 61800 is about 39.5363122791.

It can be divided in two parts, 61 and 800, that added together give a triangular number (861 = T₄₁).

The spelling of 61800 in words is "sixty-one thousand, eight hundred".