81368947 has 8 divisors (see below), whose sum is σ = 89445312. Its totient is φ = 73405800.

The previous prime is 81368897. The next prime is 81368977. The reversal of 81368947 is 74986318.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81368947 - 2¹¹ = 81366899 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81368897 and 81368906.

It is not an unprimeable number, because it can be changed into a prime (81368977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26793 + ... + 29674.

It is an arithmetic number, because the mean of its divisors is an integer number (11180664).

Almost surely, 2^81368947 is an apocalyptic number.

81368947 is a deficient number, since it is larger than the sum of its proper divisors (8076365).

81368947 is a wasteful number, since it uses less digits than its factorization.

81368947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56609.

The product of its digits is 290304, while the sum is 46.

The square root of 81368947 is about 9020.4737680457. The cubic root of 81368947 is about 433.3308066256.

The spelling of 81368947 in words is "eighty-one million, three hundred sixty-eight thousand, nine hundred forty-seven".