61564536 has 96 divisors (see below), whose sum is σ = 188697600. Its totient is φ = 18649440.

The previous prime is 61564511. The next prime is 61564549. The reversal of 61564536 is 63546516.

61564536 is a `hidden beast` number, since 6 + 1 + 5 + 645 + 3 + 6 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 61564536.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19945 + ... + 22823.

It is an arithmetic number, because the mean of its divisors is an integer number (1965600).

Almost surely, 2^61564536 is an apocalyptic number.

61564536 is a gapful number since it is divisible by the number (66) 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 61564536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94348800).

61564536 is an abundant number, since it is smaller than the sum of its proper divisors (127133064).

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

61564536 is a wasteful number, since it uses less digits than its factorization.

61564536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2911 (or 2895 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 61564536 is about 7846.3071568732. The cubic root of 61564536 is about 394.8603597627.

The spelling of 61564536 in words is "sixty-one million, five hundred sixty-four thousand, five hundred thirty-six".