61561656 has 96 divisors (see below), whose sum is σ = 181818000. Its totient is φ = 18703872.

The previous prime is 61561651. The next prime is 61561663. The reversal of 61561656 is 65616516.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a zygodrome in base 5.

It is a self number, because there is not a number n which added to its sum of digits gives 61561656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61561651) 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, 82935 + ... + 83673.

Almost surely, 2^61561656 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 61561656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90909000).

61561656 is an abundant number, since it is smaller than the sum of its proper divisors (120256344).

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

61561656 is a wasteful number, since it uses less digits than its factorization.

61561656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853 (or 846 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 61561656 is about 7846.1236289011. The cubic root of 61561656 is about 394.8542024540.

The spelling of 61561656 in words is "sixty-one million, five hundred sixty-one thousand, six hundred fifty-six".