61818781481797 has 8 divisors (see below), whose sum is σ = 62227285142616. Its totient is φ = 61410464573952.

The previous prime is 61818781481741. The next prime is 61818781481851. The reversal of 61818781481797 is 79718418781816.

It can be written as a sum of positive squares in 4 ways, for example, as 5389854419236 + 56428927062561 = 2321606^2 + 7511919^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 61818781481797 - 2¹⁹ = 61818780957509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61818781181797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46023988 + ... + 47348125.

It is an arithmetic number, because the mean of its divisors is an integer number (7778410642827).

Almost surely, 2^{61818781481797} is an apocalyptic number.

It is an amenable number.

61818781481797 is a deficient number, since it is larger than the sum of its proper divisors (408503660819).

61818781481797 is a wasteful number, since it uses less digits than its factorization.

61818781481797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93376487.

The product of its digits is 303464448, while the sum is 76.

The spelling of 61818781481797 in words is "sixty-one trillion, eight hundred eighteen billion, seven hundred eighty-one million, four hundred eighty-one thousand, seven hundred ninety-seven".