81838100 has 36 divisors (see below), whose sum is σ = 178051104. Its totient is φ = 32650080.

The previous prime is 81838093. The next prime is 81838121. The reversal of 81838100 is 183818.

It is a happy number.

It is a super-2 number, since 2×81838100² = 13394949223220000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49487 + ... + 51113.

It is an arithmetic number, because the mean of its divisors is an integer number (4945864).

Almost surely, 2^81838100 is an apocalyptic number.

It is an amenable number.

81838100 is an abundant number, since it is smaller than the sum of its proper divisors (96213004).

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

81838100 is a wasteful number, since it uses less digits than its factorization.

81838100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2144 (or 2137 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 29.

The square root of 81838100 is about 9046.4412892584. The cubic root of 81838100 is about 434.1620368001.

The spelling of 81838100 in words is "eighty-one million, eight hundred thirty-eight thousand, one hundred".