61778 has 16 divisors (see below), whose sum is σ = 103680. Its totient is φ = 27456.

The previous prime is 61757. The next prime is 61781. The reversal of 61778 is 87716.

61778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 61778.

It is an unprimeable number.

61778 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 743 + ... + 821.

It is an arithmetic number, because the mean of its divisors is an integer number (6480).

2⁶¹⁷⁷⁸ is an apocalyptic number.

61778 is a deficient number, since it is larger than the sum of its proper divisors (41902).

61778 is a wasteful number, since it uses less digits than its factorization.

61778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121.

The product of its digits is 2352, while the sum is 29.

The square root of 61778 is about 248.5518054652. The cubic root of 61778 is about 39.5316202505.

The spelling of 61778 in words is "sixty-one thousand, seven hundred seventy-eight".