81954180 has 336 divisors, whose sum is σ = 326116224. Its totient is φ = 16796160.

The previous prime is 81954179. The next prime is 81954181. The reversal of 81954180 is 8145918.

It is an interprime number because it is at equal distance from previous prime (81954179) and next prime (81954181).

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

It is not an unprimeable number, because it can be changed into a prime (81954181) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 1122624 + ... + 1122696.

It is an arithmetic number, because the mean of its divisors is an integer number (970584).

Almost surely, 2^81954180 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 81954180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163058112).

81954180 is an abundant number, since it is smaller than the sum of its proper divisors (244162044).

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

81954180 is a wasteful number, since it uses less digits than its factorization.

81954180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 81954180 is about 9052.8547983495. The cubic root of 81954180 is about 434.3672131171.

The spelling of 81954180 in words is "eighty-one million, nine hundred fifty-four thousand, one hundred eighty".