61809285852 has 72 divisors (see below), whose sum is σ = 164791186560. Its totient is φ = 19479808800.

The previous prime is 61809285851. The next prime is 61809285877. The reversal of 61809285852 is 25858290816.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61809285851) 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, 254227 + ... + 433877.

It is an arithmetic number, because the mean of its divisors is an integer number (2288766480).

Almost surely, 2^61809285852 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 61809285852, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82395593280).

61809285852 is an abundant number, since it is smaller than the sum of its proper divisors (102981900708).

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

61809285852 is a wasteful number, since it uses less digits than its factorization.

61809285852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180183 (or 180178 counting only the distinct ones).

The product of its (nonzero) digits is 2764800, while the sum is 54.

The spelling of 61809285852 in words is "sixty-one billion, eight hundred nine million, two hundred eighty-five thousand, eight hundred fifty-two".