81041580 has 48 divisors (see below), whose sum is σ = 252131040. Its totient is φ = 21610944.

The previous prime is 81041563. The next prime is 81041591. The reversal of 81041580 is 8514018.

81041580 is a `hidden beast` number, since 81 + 0 + 4 + 1 + 580 = 666.

81041580 is nontrivially palindromic in base 11.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74499 + ... + 75578.

It is an arithmetic number, because the mean of its divisors is an integer number (5252730).

Almost surely, 2^81041580 is an apocalyptic number.

It is an amenable number.

81041580 is an abundant number, since it is smaller than the sum of its proper divisors (171089460).

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

81041580 is a wasteful number, since it uses less digits than its factorization.

81041580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150095 (or 150087 counting only the distinct ones).

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

The square root of 81041580 is about 9002.3097036261. The cubic root of 81041580 is about 432.7488939055.

Adding to 81041580 its reverse (8514018), we get a palindrome (89555598).

The spelling of 81041580 in words is "eighty-one million, forty-one thousand, five hundred eighty".