61720701066 has 48 divisors (see below), whose sum is σ = 139910996160. Its totient is φ = 19627090560.

The previous prime is 61720701061. The next prime is 61720701127. The reversal of 61720701066 is 66010702716.

61720701066 is a `hidden beast` number, since 617 + 20 + 7 + 0 + 10 + 6 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 61720701066.

It is not an unprimeable number, because it can be changed into a prime (61720701061) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 39775 + ... + 353586.

It is an arithmetic number, because the mean of its divisors is an integer number (2914812420).

Almost surely, 2^61720701066 is an apocalyptic number.

61720701066 is an abundant number, since it is smaller than the sum of its proper divisors (78190295094).

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

61720701066 is a wasteful number, since it uses less digits than its factorization.

61720701066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393771 (or 393768 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The spelling of 61720701066 in words is "sixty-one billion, seven hundred twenty million, seven hundred one thousand, sixty-six".