81475199 has 16 divisors (see below), whose sum is σ = 89994240. Its totient is φ = 73301760.

The previous prime is 81475189. The next prime is 81475201. The reversal of 81475199 is 99157418.

It is a cyclic number.

It is not a de Polignac number, because 81475199 - 2¹⁶ = 81409663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81475109) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100307 + ... + 101115.

It is an arithmetic number, because the mean of its divisors is an integer number (5624640).

Almost surely, 2^81475199 is an apocalyptic number.

81475199 is a deficient number, since it is larger than the sum of its proper divisors (8519041).

81475199 is a wasteful number, since it uses less digits than its factorization.

81475199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010.

The product of its digits is 90720, while the sum is 44.

The square root of 81475199 is about 9026.3613377706. The cubic root of 81475199 is about 433.5193398042.

The spelling of 81475199 in words is "eighty-one million, four hundred seventy-five thousand, one hundred ninety-nine".