61821800 has 24 divisors (see below), whose sum is σ = 143736150. Its totient is φ = 24728640.

The previous prime is 61821761. The next prime is 61821811. The reversal of 61821800 is 812816.

It can be written as a sum of positive squares in 3 ways, for example, as 35832196 + 25989604 = 5986^2 + 5098^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 61821800.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 154355 + ... + 154754.

Almost surely, 2^61821800 is an apocalyptic number.

It is an amenable number.

61821800 is an abundant number, since it is smaller than the sum of its proper divisors (81914350).

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

61821800 is a wasteful number, since it uses less digits than its factorization.

61821800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309125 (or 309116 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 61821800 is about 7862.6840201041. The cubic root of 61821800 is about 395.4096055459.

The spelling of 61821800 in words is "sixty-one million, eight hundred twenty-one thousand, eight hundred".