81479197 has 2 divisors, whose sum is σ = 81479198. Its totient is φ = 81479196.

The previous prime is 81479173. The next prime is 81479207. The reversal of 81479197 is 79197418.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80658361 + 820836 = 8981^2 + 906^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81479197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81479117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40739598 + 40739599.

It is an arithmetic number, because the mean of its divisors is an integer number (40739599).

Almost surely, 2^81479197 is an apocalyptic number.

81479197 is the 5212-nd hex number.

It is an amenable number.

81479197 is a deficient number, since it is larger than the sum of its proper divisors (1).

81479197 is an equidigital number, since it uses as much as digits as its factorization.

81479197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 46.

The square root of 81479197 is about 9026.5827974932. The cubic root of 81479197 is about 433.5264306408.

The spelling of 81479197 in words is "eighty-one million, four hundred seventy-nine thousand, one hundred ninety-seven".