61820778 has 16 divisors (see below), whose sum is σ = 123867936. Its totient is φ = 20569200.

The previous prime is 61820777. The next prime is 61820797. The reversal of 61820778 is 87702816.

It is not an unprimeable number, because it can be changed into a prime (61820771) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5773 + ... + 12528.

It is an arithmetic number, because the mean of its divisors is an integer number (7741746).

Almost surely, 2^61820778 is an apocalyptic number.

61820778 is an abundant number, since it is smaller than the sum of its proper divisors (62047158).

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

61820778 is a wasteful number, since it uses less digits than its factorization.

61820778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18869.

The product of its (nonzero) digits is 37632, while the sum is 39.

The square root of 61820778 is about 7862.6190293057. The cubic root of 61820778 is about 395.4074266443.

The spelling of 61820778 in words is "sixty-one million, eight hundred twenty thousand, seven hundred seventy-eight".