81366254 has 4 divisors (see below), whose sum is σ = 122049384. Its totient is φ = 40683126.

The previous prime is 81366247. The next prime is 81366283. The reversal of 81366254 is 45266318.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20341562 + ... + 20341565.

It is an arithmetic number, because the mean of its divisors is an integer number (30512346).

Almost surely, 2^81366254 is an apocalyptic number.

81366254 is a deficient number, since it is larger than the sum of its proper divisors (40683130).

81366254 is a wasteful number, since it uses less digits than its factorization.

81366254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40683129.

The product of its digits is 34560, while the sum is 35.

The square root of 81366254 is about 9020.3244952718. The cubic root of 81366254 is about 433.3260260438.

The spelling of 81366254 in words is "eighty-one million, three hundred sixty-six thousand, two hundred fifty-four".