61685012779 has 4 divisors (see below), whose sum is σ = 66430013776. Its totient is φ = 56940011784.

The previous prime is 61685012747. The next prime is 61685012791. The reversal of 61685012779 is 97721058616.

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 61685012779 - 2⁵ = 61685012747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61685012729) 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, 2372500479 + ... + 2372500504.

It is an arithmetic number, because the mean of its divisors is an integer number (16607503444).

Almost surely, 2^61685012779 is an apocalyptic number.

61685012779 is a deficient number, since it is larger than the sum of its proper divisors (4745000997).

61685012779 is a wasteful number, since it uses less digits than its factorization.

61685012779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4745000996.

The product of its (nonzero) digits is 1270080, while the sum is 52.

The spelling of 61685012779 in words is "sixty-one billion, six hundred eighty-five million, twelve thousand, seven hundred seventy-nine".