81042266 has 4 divisors (see below), whose sum is σ = 121563402. Its totient is φ = 40521132.

The previous prime is 81042259. The next prime is 81042289. The reversal of 81042266 is 66224018.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 77352025 + 3690241 = 8795^2 + 1921^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20260565 + ... + 20260568.

Almost surely, 2^81042266 is an apocalyptic number.

81042266 is a deficient number, since it is larger than the sum of its proper divisors (40521136).

81042266 is a wasteful number, since it uses less digits than its factorization.

81042266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40521135.

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 81042266 is about 9002.3478048785. The cubic root of 81042266 is about 432.7501149450.

The spelling of 81042266 in words is "eighty-one million, forty-two thousand, two hundred sixty-six".