61866644666816 has 28 divisors (see below), whose sum is σ = 133927225104120. Its totient is φ = 28121202120960.

The previous prime is 61866644666789. The next prime is 61866644666921.

61866644666816 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43939377611 + ... + 43939379018.

It is an arithmetic number, because the mean of its divisors is an integer number (4783115182290).

Almost surely, 2^{61866644666816} is an apocalyptic number.

It is an amenable number.

61866644666816 is an abundant number, since it is smaller than the sum of its proper divisors (72060580437304).

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

61866644666816 is a wasteful number, since it uses less digits than its factorization.

61866644666816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87878756652 (or 87878756642 counting only the distinct ones).

The product of its digits is 1719926784, while the sum is 74.

The spelling of 61866644666816 in words is "sixty-one trillion, eight hundred sixty-six billion, six hundred forty-four million, six hundred sixty-six thousand, eight hundred sixteen".