61755865578 has 48 divisors (see below), whose sum is σ = 146083313376. Its totient is φ = 18699167520.

The previous prime is 61755865573. The next prime is 61755865597. The reversal of 61755865578 is 87556855716.

61755865578 is a `hidden beast` number, since 6 + 1 + 7 + 5 + 58 + 6 + 5 + 578 = 666.

It is not an unprimeable number, because it can be changed into a prime (61755865573) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 130725 + ... + 374967.

It is an arithmetic number, because the mean of its divisors is an integer number (3043402362).

Almost surely, 2^61755865578 is an apocalyptic number.

61755865578 is an abundant number, since it is smaller than the sum of its proper divisors (84327447798).

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

61755865578 is a wasteful number, since it uses less digits than its factorization.

61755865578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245539 (or 245536 counting only the distinct ones).

The product of its digits is 70560000, while the sum is 63.

The spelling of 61755865578 in words is "sixty-one billion, seven hundred fifty-five million, eight hundred sixty-five thousand, five hundred seventy-eight".