61685522208 has 144 divisors (see below), whose sum is σ = 184825761120. Its totient is φ = 19461178368.

The previous prime is 61685522183. The next prime is 61685522231. The reversal of 61685522208 is 80222558616.

It is a happy number.

61685522208 is a `hidden beast` number, since 61 + 68 + 5 + 522 + 2 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×61685522208² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6490516 + ... + 6500012.

It is an arithmetic number, because the mean of its divisors is an integer number (1283512230).

Almost surely, 2^61685522208 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 61685522208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92412880560).

61685522208 is an abundant number, since it is smaller than the sum of its proper divisors (123140238912).

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

61685522208 is a wasteful number, since it uses less digits than its factorization.

61685522208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10719 (or 10708 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 45.

The spelling of 61685522208 in words is "sixty-one billion, six hundred eighty-five million, five hundred twenty-two thousand, two hundred eight".