61608700521 has 63 divisors (see below), whose sum is σ = 95968566421. Its totient is φ = 39531076704.

The previous prime is 61608700501. The next prime is 61608700523. The reversal of 61608700521 is 12500780616.

The square root of 61608700521 is 248211.

It is a perfect power (a square), and thus also a powerful number.

61608700521 is a `hidden beast` number, since 6 + 1 + 60 + 8 + 70 + 0 + 521 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 15325202025 + 46283498496 = 123795^2 + 215136^2 .

It is a de Polignac number, because none of the positive numbers 2^k-61608700521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61608700523) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 194349055 + ... + 194349371.

Almost surely, 2^61608700521 is an apocalyptic number.

61608700521 is the 248211-st square number.

61608700521 is the 124106-th centered octagonal number.

It is an amenable number.

61608700521 is a deficient number, since it is larger than the sum of its proper divisors (34359865900).

61608700521 is an frugal number, since it uses more digits than its factorization.

61608700521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

Multiplying 61608700521 by its sum of digits (36), we get a square (2217913218756 = 1489266²).

It can be divided in two parts, 61608 and 700521, that added together give a square (762129 = 873²).

The spelling of 61608700521 in words is "sixty-one billion, six hundred eight million, seven hundred thousand, five hundred twenty-one".