61561616 has 40 divisors (see below), whose sum is σ = 125509824. Its totient is φ = 29194880.

The previous prime is 61561613. The next prime is 61561631. The reversal of 61561616 is 61616516.

61561616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (61561613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47570 + ... + 48846.

Almost surely, 2^61561616 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 61561616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62754912).

61561616 is an abundant number, since it is smaller than the sum of its proper divisors (63948208).

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

61561616 is a wasteful number, since it uses less digits than its factorization.

61561616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439 (or 1433 counting only the distinct ones).

The product of its digits is 6480, while the sum is 32.

The square root of 61561616 is about 7846.1210798713. The cubic root of 61561616 is about 394.8541169344.

The spelling of 61561616 in words is "sixty-one million, five hundred sixty-one thousand, six hundred sixteen".