81947938 has 8 divisors (see below), whose sum is σ = 125780688. Its totient is φ = 40021044.

The previous prime is 81947927. The next prime is 81947947. The reversal of 81947938 is 83974918.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 81947891 and 81947900.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 476356 + ... + 476527.

It is an arithmetic number, because the mean of its divisors is an integer number (15722586).

Almost surely, 2^81947938 is an apocalyptic number.

81947938 is a deficient number, since it is larger than the sum of its proper divisors (43832750).

81947938 is a wasteful number, since it uses less digits than its factorization.

81947938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952928.

The product of its digits is 435456, while the sum is 49.

The square root of 81947938 is about 9052.5100386578. The cubic root of 81947938 is about 434.3561850484.

The spelling of 81947938 in words is "eighty-one million, nine hundred forty-seven thousand, nine hundred thirty-eight".