81089775 has 48 divisors (see below), whose sum is σ = 160441120. Its totient is φ = 39916800.

The previous prime is 81089753. The next prime is 81089783. The reversal of 81089775 is 57798018.

It is not a de Polignac number, because 81089775 - 2⁹ = 81089263 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81089775.

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, 4155 + ... + 13395.

Almost surely, 2^81089775 is an apocalyptic number.

81089775 is a deficient number, since it is larger than the sum of its proper divisors (79351345).

81089775 is a wasteful number, since it uses less digits than its factorization.

81089775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9273 (or 9262 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 81089775 is about 9004.9861188122. The cubic root of 81089775 is about 432.8346614005.

The spelling of 81089775 in words is "eighty-one million, eighty-nine thousand, seven hundred seventy-five".