61707728080 has 20 divisors (see below), whose sum is σ = 143470467972. Its totient is φ = 24683091200.

The previous prime is 61707728053. The next prime is 61707728081. The reversal of 61707728080 is 8082770716.

It can be written as a sum of positive squares in 2 ways, for example, as 38638978624 + 23068749456 = 196568^2 + 151884^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 61707728080.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61707728081) 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, 385673221 + ... + 385673380.

Almost surely, 2^61707728080 is an apocalyptic number.

It is an amenable number.

61707728080 is an abundant number, since it is smaller than the sum of its proper divisors (81762739892).

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

61707728080 is a wasteful number, since it uses less digits than its factorization.

61707728080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 771346614 (or 771346608 counting only the distinct ones).

The product of its (nonzero) digits is 263424, while the sum is 46.

The spelling of 61707728080 in words is "sixty-one billion, seven hundred seven million, seven hundred twenty-eight thousand, eighty".