61691318763 has 4 divisors (see below), whose sum is σ = 82255091688. Its totient is φ = 41127545840.

The previous prime is 61691318719. The next prime is 61691318803. The reversal of 61691318763 is 36781319616.

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

It is a cyclic number.

It is not a de Polignac number, because 61691318763 - 2⁹ = 61691318251 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61691318713) 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, 10281886458 + ... + 10281886463.

It is an arithmetic number, because the mean of its divisors is an integer number (20563772922).

Almost surely, 2^61691318763 is an apocalyptic number.

61691318763 is a deficient number, since it is larger than the sum of its proper divisors (20563772925).

61691318763 is a wasteful number, since it uses less digits than its factorization.

61691318763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20563772924.

The product of its digits is 979776, while the sum is 51.

The spelling of 61691318763 in words is "sixty-one billion, six hundred ninety-one million, three hundred eighteen thousand, seven hundred sixty-three".