81236494 has 8 divisors (see below), whose sum is σ = 122046768. Its totient is φ = 40554240.

The previous prime is 81236471. The next prime is 81236513. The reversal of 81236494 is 49463218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30402 + ... + 32965.

It is an arithmetic number, because the mean of its divisors is an integer number (15255846).

Almost surely, 2^81236494 is an apocalyptic number.

81236494 is a deficient number, since it is larger than the sum of its proper divisors (40810274).

81236494 is a wasteful number, since it uses less digits than its factorization.

81236494 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64010.

The product of its digits is 41472, while the sum is 37.

The square root of 81236494 is about 9013.1289794388. The cubic root of 81236494 is about 433.0955525193.

The spelling of 81236494 in words is "eighty-one million, two hundred thirty-six thousand, four hundred ninety-four".