81118207 has 2 divisors, whose sum is σ = 81118208. Its totient is φ = 81118206.

The previous prime is 81118199. The next prime is 81118211. The reversal of 81118207 is 70281118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81118207 - 2³ = 81118199 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 (81118267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40559103 + 40559104.

It is an arithmetic number, because the mean of its divisors is an integer number (40559104).

Almost surely, 2^81118207 is an apocalyptic number.

81118207 is a deficient number, since it is larger than the sum of its proper divisors (1).

81118207 is an equidigital number, since it uses as much as digits as its factorization.

81118207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 896, while the sum is 28.

The square root of 81118207 is about 9006.5646614011. The cubic root of 81118207 is about 432.8852428582.

The spelling of 81118207 in words is "eighty-one million, one hundred eighteen thousand, two hundred seven".