81400106 has 4 divisors (see below), whose sum is σ = 122100162. Its totient is φ = 40700052.

The previous prime is 81400093. The next prime is 81400171. The reversal of 81400106 is 60100418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 51051025 + 30349081 = 7145^2 + 5509^2 .

It is a super-2 number, since 2×81400106² = 13251954513622472, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20350025 + ... + 20350028.

Almost surely, 2^81400106 is an apocalyptic number.

81400106 is a deficient number, since it is larger than the sum of its proper divisors (40700056).

81400106 is a wasteful number, since it uses less digits than its factorization.

81400106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40700055.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 81400106 is about 9022.2007293121. The cubic root of 81400106 is about 433.3861120461.

The spelling of 81400106 in words is "eighty-one million, four hundred thousand, one hundred six".