81475193 has 4 divisors (see below), whose sum is σ = 81535908. Its totient is φ = 81414480.

The previous prime is 81475189. The next prime is 81475201. The reversal of 81475193 is 39157418.

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

It can be written as a sum of positive squares in 2 ways, for example, as 47927929 + 33547264 = 6923^2 + 5792^2 .

It is a cyclic number.

It is not a de Polignac number, because 81475193 - 2² = 81475189 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81405193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28298 + ... + 31043.

It is an arithmetic number, because the mean of its divisors is an integer number (20383977).

Almost surely, 2^81475193 is an apocalyptic number.

It is an amenable number.

81475193 is a deficient number, since it is larger than the sum of its proper divisors (60715).

81475193 is a wasteful number, since it uses less digits than its factorization.

81475193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60714.

The product of its digits is 30240, while the sum is 38.

The square root of 81475193 is about 9026.3610054108. The cubic root of 81475193 is about 433.5193291625.

The spelling of 81475193 in words is "eighty-one million, four hundred seventy-five thousand, one hundred ninety-three".