61810681049 has 4 divisors (see below), whose sum is σ = 66565348836. Its totient is φ = 57056013264.

The previous prime is 61810681013. The next prime is 61810681061. The reversal of 61810681049 is 94018601816.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22509601024 + 39301080025 = 150032^2 + 198245^2 .

It is a cyclic number.

It is not a de Polignac number, because 61810681049 - 2¹² = 61810676953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61810681549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2377333874 + ... + 2377333899.

It is an arithmetic number, because the mean of its divisors is an integer number (16641337209).

Almost surely, 2^61810681049 is an apocalyptic number.

It is an amenable number.

61810681049 is a deficient number, since it is larger than the sum of its proper divisors (4754667787).

61810681049 is a wasteful number, since it uses less digits than its factorization.

61810681049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4754667786.

The product of its (nonzero) digits is 82944, while the sum is 44.

The spelling of 61810681049 in words is "sixty-one billion, eight hundred ten million, six hundred eighty-one thousand, forty-nine".