61820 has 24 divisors (see below), whose sum is σ = 142128. Its totient is φ = 22400.

The previous prime is 61819. The next prime is 61837. The reversal of 61820 is 2816.

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, 80 + ... + 360.

It is an arithmetic number, because the mean of its divisors is an integer number (5922).

2⁶¹⁸²⁰ 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 61820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71064).

61820 is an abundant number, since it is smaller than the sum of its proper divisors (80308).

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

61820 is a wasteful number, since it uses less digits than its factorization.

61820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301 (or 299 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 61820 is about 248.6362805385. The cubic root of 61820 is about 39.5405767934.

Adding to 61820 its product of nonzero digits (96), we get a palindrome (61916).

The spelling of 61820 in words is "sixty-one thousand, eight hundred twenty".