61866816 has 84 divisors (see below), whose sum is σ = 179990496. Its totient is φ = 18740480.

The previous prime is 61866811. The next prime is 61866817.

61866816 is nontrivially palindromic in base 10.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61866811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21901 + ... + 24563.

It is an arithmetic number, because the mean of its divisors is an integer number (2142744).

Almost surely, 2^61866816 is an apocalyptic number.

61866816 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61866816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89995248).

61866816 is an abundant number, since it is smaller than the sum of its proper divisors (118123680).

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

61866816 is a wasteful number, since it uses less digits than its factorization.

61866816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2700 (or 2679 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 61866816 is about 7865.5461348847. The cubic root of 61866816 is about 395.5055557350.

The spelling of 61866816 in words is "sixty-one million, eight hundred sixty-six thousand, eight hundred sixteen".