61778725878 has 64 divisors (see below), whose sum is σ = 129358649088. Its totient is φ = 19649589120.

The previous prime is 61778725867. The next prime is 61778725907. The reversal of 61778725878 is 87852787716.

It is a super-2 number, since 2×61778725878² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4692501 + ... + 4705647.

It is an arithmetic number, because the mean of its divisors is an integer number (2021228892).

Almost surely, 2^61778725878 is an apocalyptic number.

61778725878 is an abundant number, since it is smaller than the sum of its proper divisors (67579923210).

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

61778725878 is a wasteful number, since it uses less digits than its factorization.

61778725878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13597.

The product of its digits is 73758720, while the sum is 66.

The spelling of 61778725878 in words is "sixty-one billion, seven hundred seventy-eight million, seven hundred twenty-five thousand, eight hundred seventy-eight".