61800820 has 24 divisors (see below), whose sum is σ = 130977000. Its totient is φ = 24492672.

The previous prime is 61800803. The next prime is 61800833. The reversal of 61800820 is 2800816.

61800820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 992016 + 60808804 = 996^2 + 7798^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11995 + ... + 16354.

It is an arithmetic number, because the mean of its divisors is an integer number (5457375).

Almost surely, 2^61800820 is an apocalyptic number.

It is an amenable number.

61800820 is an abundant number, since it is smaller than the sum of its proper divisors (69176180).

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

61800820 is a wasteful number, since it uses less digits than its factorization.

61800820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28467 (or 28465 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 61800820 is about 7861.3497568802. The cubic root of 61800820 is about 395.3648714223.

The spelling of 61800820 in words is "sixty-one million, eight hundred thousand, eight hundred twenty".