81213127 has 2 divisors, whose sum is σ = 81213128. Its totient is φ = 81213126.

The previous prime is 81213103. The next prime is 81213151. The reversal of 81213127 is 72131218.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (81213103) and next prime (81213151).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81213127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81213527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40606563 + 40606564.

It is an arithmetic number, because the mean of its divisors is an integer number (40606564).

Almost surely, 2^81213127 is an apocalyptic number.

81213127 is a deficient number, since it is larger than the sum of its proper divisors (1).

81213127 is an equidigital number, since it uses as much as digits as its factorization.

81213127 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 25.

The square root of 81213127 is about 9011.8326105182. The cubic root of 81213127 is about 433.0540230960.

The spelling of 81213127 in words is "eighty-one million, two hundred thirteen thousand, one hundred twenty-seven".