81002880 has 384 divisors, whose sum is σ = 334152000. Its totient is φ = 18063360.

The previous prime is 81002869. The next prime is 81002897. The reversal of 81002880 is 8820018.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×81002880² = 13122933136588800, which contains 22 as substring.

It is a nialpdrome in base 14.

It is a zygodrome in base 14.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1975660 + ... + 1975700.

Almost surely, 2^81002880 is an apocalyptic number.

81002880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81002880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167076000).

81002880 is an abundant number, since it is smaller than the sum of its proper divisors (253149120).

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

81002880 is a wasteful number, since it uses less digits than its factorization.

81002880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 81002880 is about 9000.1599985778. The cubic root of 81002880 is about 432.6799990299.

Adding to 81002880 its reverse (8820018), we get a palindrome (89822898).

The spelling of 81002880 in words is "eighty-one million, two thousand, eight hundred eighty".