61355985264 has 480 divisors, whose sum is σ = 207363811200. Its totient is φ = 16572211200.

The previous prime is 61355985221. The next prime is 61355985287. The reversal of 61355985264 is 46258955316.

61355985264 is a `hidden beast` number, since 6 + 1 + 3 + 559 + 85 + 2 + 6 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 61355985264.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 338983254 + ... + 338983434.

It is an arithmetic number, because the mean of its divisors is an integer number (432007940).

Almost surely, 2^61355985264 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 61355985264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103681905600).

61355985264 is an abundant number, since it is smaller than the sum of its proper divisors (146007825936).

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

61355985264 is a wasteful number, since it uses less digits than its factorization.

61355985264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449 (or 440 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 54.

The spelling of 61355985264 in words is "sixty-one billion, three hundred fifty-five million, nine hundred eighty-five thousand, two hundred sixty-four".