61781666093 has 8 divisors (see below), whose sum is σ = 70704746112. Its totient is φ = 52882868016.

The previous prime is 61781666071. The next prime is 61781666099. The reversal of 61781666093 is 39066618716.

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-61781666093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61781666099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6065030 + ... + 6075207.

It is an arithmetic number, because the mean of its divisors is an integer number (8838093264).

Almost surely, 2^61781666093 is an apocalyptic number.

It is an amenable number.

61781666093 is a deficient number, since it is larger than the sum of its proper divisors (8923080019).

61781666093 is a wasteful number, since it uses less digits than its factorization.

61781666093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12140971.

The product of its (nonzero) digits is 1959552, while the sum is 53.

The spelling of 61781666093 in words is "sixty-one billion, seven hundred eighty-one million, six hundred sixty-six thousand, ninety-three".