61801813128 has 128 divisors (see below), whose sum is σ = 170980300800. Its totient is φ = 18458668800.

The previous prime is 61801813121. The next prime is 61801813163. The reversal of 61801813128 is 82131810816.

It is not an unprimeable number, because it can be changed into a prime (61801813121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13783575 + ... + 13788057.

It is an arithmetic number, because the mean of its divisors is an integer number (1335783600).

Almost surely, 2^61801813128 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 61801813128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85490150400).

61801813128 is an abundant number, since it is smaller than the sum of its proper divisors (109178487672).

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

61801813128 is a wasteful number, since it uses less digits than its factorization.

61801813128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5243 (or 5239 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 39.

The spelling of 61801813128 in words is "sixty-one billion, eight hundred one million, eight hundred thirteen thousand, one hundred twenty-eight".