81838938 has 16 divisors (see below), whose sum is σ = 167160960. Its totient is φ = 26699136.

The previous prime is 81838937. The next prime is 81838951. The reversal of 81838938 is 83983818.

It is a happy number.

It is a super-2 number, since 2×81838938² = 13395223545935688, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81838937) 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, 144823 + ... + 145386.

It is an arithmetic number, because the mean of its divisors is an integer number (10447560).

Almost surely, 2^81838938 is an apocalyptic number.

81838938 is an abundant number, since it is smaller than the sum of its proper divisors (85322022).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81838938 is a wasteful number, since it uses less digits than its factorization.

81838938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290261.

The product of its digits is 331776, while the sum is 48.

The square root of 81838938 is about 9046.4876056954. The cubic root of 81838938 is about 434.1635186956.

The spelling of 81838938 in words is "eighty-one million, eight hundred thirty-eight thousand, nine hundred thirty-eight".