61820780 has 96 divisors (see below), whose sum is σ = 157538304. Its totient is φ = 19920384.

The previous prime is 61820777. The next prime is 61820797. The reversal of 61820780 is 8702816.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 234929 + ... + 235191.

It is an arithmetic number, because the mean of its divisors is an integer number (1641024).

Almost surely, 2^61820780 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 61820780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78769152).

61820780 is an abundant number, since it is smaller than the sum of its proper divisors (95717524).

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

61820780 is a wasteful number, since it uses less digits than its factorization.

61820780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 61820780 is about 7862.6191564898. The cubic root of 61820780 is about 395.4074309084.

The spelling of 61820780 in words is "sixty-one million, eight hundred twenty thousand, seven hundred eighty".