81485138 has 40 divisors (see below), whose sum is σ = 145203840. Its totient is φ = 34286280.

The previous prime is 81485123. The next prime is 81485147. The reversal of 81485138 is 83158418.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 340823 + ... + 341061.

It is an arithmetic number, because the mean of its divisors is an integer number (3630096).

Almost surely, 2^81485138 is an apocalyptic number.

81485138 is a deficient number, since it is larger than the sum of its proper divisors (63718702).

81485138 is an equidigital number, since it uses as much as digits as its factorization.

81485138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340 (or 319 counting only the distinct ones).

The product of its digits is 30720, while the sum is 38.

The square root of 81485138 is about 9026.9118750545. The cubic root of 81485138 is about 433.5369671459.

The spelling of 81485138 in words is "eighty-one million, four hundred eighty-five thousand, one hundred thirty-eight".