81017938 has 32 divisors (see below), whose sum is σ = 135979200. Its totient is φ = 36033984.

The previous prime is 81017933. The next prime is 81017947. The reversal of 81017938 is 83971018.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a junction number, because it is equal to n+sod(n) for n = 81017897 and 81017906.

It is not an unprimeable number, because it can be changed into a prime (81017933) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39781 + ... + 41767.

It is an arithmetic number, because the mean of its divisors is an integer number (4249350).

Almost surely, 2^81017938 is an apocalyptic number.

81017938 is a deficient number, since it is larger than the sum of its proper divisors (54961262).

81017938 is a wasteful number, since it uses less digits than its factorization.

81017938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2074.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 81017938 is about 9000.9965003882. The cubic root of 81017938 is about 432.7068083308.

The spelling of 81017938 in words is "eighty-one million, seventeen thousand, nine hundred thirty-eight".