61686939964238 has 4 divisors (see below), whose sum is σ = 92530409946360. Its totient is φ = 30843469982118.

The previous prime is 61686939964141. The next prime is 61686939964277. The reversal of 61686939964238 is 83246993968616.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15421734991058 + ... + 15421734991061.

It is an arithmetic number, because the mean of its divisors is an integer number (23132602486590).

Almost surely, 2^{61686939964238} is an apocalyptic number.

61686939964238 is a deficient number, since it is larger than the sum of its proper divisors (30843469982122).

61686939964238 is a wasteful number, since it uses less digits than its factorization.

61686939964238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30843469982121.

The product of its digits is 4353564672, while the sum is 80.

The spelling of 61686939964238 in words is "sixty-one trillion, six hundred eighty-six billion, nine hundred thirty-nine million, nine hundred sixty-four thousand, two hundred thirty-eight".