81150987 has 4 divisors (see below), whose sum is σ = 108201320. Its totient is φ = 54100656.

The previous prime is 81150977. The next prime is 81151043. The reversal of 81150987 is 78905118.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81150987 - 2¹⁰ = 81149963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81150907) 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 3 ways as a sum of consecutive naturals, for example, 13525162 + ... + 13525167.

It is an arithmetic number, because the mean of its divisors is an integer number (27050330).

Almost surely, 2^81150987 is an apocalyptic number.

81150987 is a deficient number, since it is larger than the sum of its proper divisors (27050333).

81150987 is a wasteful number, since it uses less digits than its factorization.

81150987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27050332.

The product of its (nonzero) digits is 20160, while the sum is 39.

The square root of 81150987 is about 9008.3842613423. The cubic root of 81150987 is about 432.9435448836.

The spelling of 81150987 in words is "eighty-one million, one hundred fifty thousand, nine hundred eighty-seven".