61191683818 has 4 divisors (see below), whose sum is σ = 91787525730. Its totient is φ = 30595841908.

The previous prime is 61191683807. The next prime is 61191683843. The reversal of 61191683818 is 81838619116.

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

It can be written as a sum of positive squares in only one way, i.e., 60862370209 + 329313609 = 246703^2 + 18147^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15297920953 + ... + 15297920956.

Almost surely, 2^61191683818 is an apocalyptic number.

61191683818 is a deficient number, since it is larger than the sum of its proper divisors (30595841912).

61191683818 is a wasteful number, since it uses less digits than its factorization.

61191683818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30595841911.

The product of its digits is 497664, while the sum is 52.

The spelling of 61191683818 in words is "sixty-one billion, one hundred ninety-one million, six hundred eighty-three thousand, eight hundred eighteen".