81501480 has 192 divisors, whose sum is σ = 280051200. Its totient is φ = 20528640.

The previous prime is 81501463. The next prime is 81501499. The reversal of 81501480 is 8410518.

81501480 is a `hidden beast` number, since 81 + 501 + 4 + 80 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 747666 + ... + 747774.

It is an arithmetic number, because the mean of its divisors is an integer number (1458600).

Almost surely, 2^81501480 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 81501480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140025600).

81501480 is an abundant number, since it is smaller than the sum of its proper divisors (198549720).

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

81501480 is a wasteful number, since it uses less digits than its factorization.

81501480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 81501480 is about 9027.8170118806. The cubic root of 81501480 is about 433.5659474308.

Adding to 81501480 its reverse (8410518), we get a palindrome (89911998).

The spelling of 81501480 in words is "eighty-one million, five hundred one thousand, four hundred eighty".