61681436249616 has 120 divisors (see below), whose sum is σ = 173300172625944. Its totient is φ = 20479845734400.

The previous prime is 61681436249591. The next prime is 61681436249683. The reversal of 61681436249616 is 61694263418616.

61681436249616 is a `hidden beast` number, since 6 + 1 + 6 + 8 + 1 + 4 + 3 + 6 + 2 + 4 + 9 + 616 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 933503792400 + 60747932457216 = 966180^2 + 7794096^2 .

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

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 58868740 + ... + 59907356.

Almost surely, 2^{61681436249616} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61681436249616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86650086312972).

61681436249616 is an abundant number, since it is smaller than the sum of its proper divisors (111618736376328).

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

61681436249616 is a wasteful number, since it uses less digits than its factorization.

61681436249616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1040249 (or 1040240 counting only the distinct ones).

The product of its digits is 53747712, while the sum is 63.

The spelling of 61681436249616 in words is "sixty-one trillion, six hundred eighty-one billion, four hundred thirty-six million, two hundred forty-nine thousand, six hundred sixteen".