81046980 has 180 divisors, whose sum is σ = 296046828. Its totient is φ = 18506880.

The previous prime is 81046961. The next prime is 81046981. The reversal of 81046980 is 8964018.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 38118276 + 42928704 = 6174^2 + 6552^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×81046980² = 13137225934240800, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81046981) 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 59 ways as a sum of consecutive naturals, for example, 78870 + ... + 79890.

Almost surely, 2^81046980 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 81046980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148023414).

81046980 is an abundant number, since it is smaller than the sum of its proper divisors (214999848).

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

81046980 is a wasteful number, since it uses less digits than its factorization.

81046980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056 (or 1038 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81046980 is about 9002.6096216597. The cubic root of 81046980 is about 432.7585054001.

The spelling of 81046980 in words is "eighty-one million, forty-six thousand, nine hundred eighty".