81266123 has 2 divisors, whose sum is σ = 81266124. Its totient is φ = 81266122.

The previous prime is 81266111. The next prime is 81266131. The reversal of 81266123 is 32166218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81266123 - 2²⁰ = 80217547 is a prime.

It is a super-2 number, since 2×81266123² = 13208365494902258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81266623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40633061 + 40633062.

It is an arithmetic number, because the mean of its divisors is an integer number (40633062).

Almost surely, 2^81266123 is an apocalyptic number.

81266123 is a deficient number, since it is larger than the sum of its proper divisors (1).

81266123 is an equidigital number, since it uses as much as digits as its factorization.

81266123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 81266123 is about 9014.7724874231. The cubic root of 81266123 is about 433.1481997461.

The spelling of 81266123 in words is "eighty-one million, two hundred sixty-six thousand, one hundred twenty-three".