61681051584 has 392 divisors, whose sum is σ = 204585204240. Its totient is φ = 18327969792.

The previous prime is 61681051559. The next prime is 61681051589. The reversal of 61681051584 is 48515018616.

61681051584 is a `hidden beast` number, since 6 + 1 + 6 + 8 + 10 + 51 + 584 = 666.

61681051584 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61681051589) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 15067842 + ... + 15071934.

Almost surely, 2^61681051584 is an apocalyptic number.

61681051584 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61681051584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102292602120).

61681051584 is an abundant number, since it is smaller than the sum of its proper divisors (142904152656).

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

61681051584 is a wasteful number, since it uses less digits than its factorization.

61681051584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4159 (or 4134 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 61681051584 in words is "sixty-one billion, six hundred eighty-one million, fifty-one thousand, five hundred eighty-four".