81887541 has 16 divisors (see below), whose sum is σ = 110476800. Its totient is φ = 53949168.

The previous prime is 81887539. The next prime is 81887543. The reversal of 81887541 is 14578818.

It is an interprime number because it is at equal distance from previous prime (81887539) and next prime (81887543).

It is not a de Polignac number, because 81887541 - 2¹ = 81887539 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81887493 and 81887502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81887543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149430 + ... + 149976.

It is an arithmetic number, because the mean of its divisors is an integer number (6904800).

Almost surely, 2^81887541 is an apocalyptic number.

It is an amenable number.

81887541 is a deficient number, since it is larger than the sum of its proper divisors (28589259).

81887541 is a wasteful number, since it uses less digits than its factorization.

81887541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048.

The product of its digits is 71680, while the sum is 42.

The square root of 81887541 is about 9049.1734981710. The cubic root of 81887541 is about 434.2494495661.

It can be divided in two parts, 81887 and 541, that added together give a palindrome (82428).

The spelling of 81887541 in words is "eighty-one million, eight hundred eighty-seven thousand, five hundred forty-one".