61359143981 has 8 divisors (see below), whose sum is σ = 61605874680. Its totient is φ = 61112475648.

The previous prime is 61359143939. The next prime is 61359144017. The reversal of 61359143981 is 18934195316.

It can be written as a sum of positive squares in 4 ways, for example, as 17355691081 + 44003452900 = 131741^2 + 209770^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61359143981 is a prime.

It is a super-2 number, since 2×61359143981² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61359143581) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3813305 + ... + 3829361.

It is an arithmetic number, because the mean of its divisors is an integer number (7700734335).

Almost surely, 2^61359143981 is an apocalyptic number.

It is an amenable number.

61359143981 is a deficient number, since it is larger than the sum of its proper divisors (246730699).

61359143981 is a wasteful number, since it uses less digits than its factorization.

61359143981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31183.

The product of its digits is 699840, while the sum is 50.

The spelling of 61359143981 in words is "sixty-one billion, three hundred fifty-nine million, one hundred forty-three thousand, nine hundred eighty-one".