61685012780 has 48 divisors (see below), whose sum is σ = 136530266880. Its totient is φ = 23345558208.

The previous prime is 61685012747. The next prime is 61685012791. The reversal of 61685012780 is 8721058616.

It is a happy number.

It is a super-3 number, since 3×61685012780³ (a number of 33 digits) contains 333 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 195929 + ... + 402191.

It is an arithmetic number, because the mean of its divisors is an integer number (2844380560).

Almost surely, 2^61685012780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61685012780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68265133440).

61685012780 is an abundant number, since it is smaller than the sum of its proper divisors (74845254100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61685012780 is a wasteful number, since it uses less digits than its factorization.

61685012780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207078 (or 207076 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 44.

The spelling of 61685012780 in words is "sixty-one billion, six hundred eighty-five million, twelve thousand, seven hundred eighty".