81143075 has 12 divisors (see below), whose sum is σ = 108357648. Its totient is φ = 59920800.

The previous prime is 81143071. The next prime is 81143081. The reversal of 81143075 is 57034118.

It is not a de Polignac number, because 81143075 - 2² = 81143071 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81143071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 124511 + ... + 125160.

It is an arithmetic number, because the mean of its divisors is an integer number (9029804).

Almost surely, 2^81143075 is an apocalyptic number.

81143075 is a deficient number, since it is larger than the sum of its proper divisors (27214573).

81143075 is a wasteful number, since it uses less digits than its factorization.

81143075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249694 (or 249689 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 81143075 is about 9007.9451041844. The cubic root of 81143075 is about 432.9294741545.

The spelling of 81143075 in words is "eighty-one million, one hundred forty-three thousand, seventy-five".