81170293 has 2 divisors, whose sum is σ = 81170294. Its totient is φ = 81170292.

The previous prime is 81170281. The next prime is 81170311. The reversal of 81170293 is 39207118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68260644 + 12909649 = 8262^2 + 3593^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81170293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81170213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40585146 + 40585147.

It is an arithmetic number, because the mean of its divisors is an integer number (40585147).

Almost surely, 2^81170293 is an apocalyptic number.

It is an amenable number.

81170293 is a deficient number, since it is larger than the sum of its proper divisors (1).

81170293 is an equidigital number, since it uses as much as digits as its factorization.

81170293 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 81170293 is about 9009.4557549277. The cubic root of 81170293 is about 432.9778749049.

The spelling of 81170293 in words is "eighty-one million, one hundred seventy thousand, two hundred ninety-three".