61989018 has 80 divisors (see below), whose sum is σ = 156228576. Its totient is φ = 16299360.

The previous prime is 61989017. The next prime is 61989019. The reversal of 61989018 is 81098916.

61989018 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (61989017) and next prime (61989019).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61989017) 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 39 ways as a sum of consecutive naturals, for example, 187113 + ... + 187443.

Almost surely, 2^61989018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61989018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78114288).

61989018 is an abundant number, since it is smaller than the sum of its proper divisors (94239558).

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

61989018 is a wasteful number, since it uses less digits than its factorization.

61989018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377 (or 356 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 42.

The square root of 61989018 is about 7873.3104854311. The cubic root of 61989018 is about 395.7657910045.

The spelling of 61989018 in words is "sixty-one million, nine hundred eighty-nine thousand, eighteen".