61686528 has 72 divisors (see below), whose sum is σ = 169537536. Its totient is φ = 19891200.

The previous prime is 61686487. The next prime is 61686551. The reversal of 61686528 is 82568616.

It is a self number, because there is not a number n which added to its sum of digits gives 61686528.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22513 + ... + 25103.

It is an arithmetic number, because the mean of its divisors is an integer number (2354688).

Almost surely, 2^61686528 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 61686528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84768768).

61686528 is an abundant number, since it is smaller than the sum of its proper divisors (107851008).

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

61686528 is a wasteful number, since it uses less digits than its factorization.

61686528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2641 (or 2627 counting only the distinct ones).

The product of its digits is 138240, while the sum is 42.

The square root of 61686528 is about 7854.0771577570. The cubic root of 61686528 is about 395.1209969546.

The spelling of 61686528 in words is "sixty-one million, six hundred eighty-six thousand, five hundred twenty-eight".