81445406 has 16 divisors (see below), whose sum is σ = 139839360. Its totient is φ = 34850520.

The previous prime is 81445387. The next prime is 81445423. The reversal of 81445406 is 60454418.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5465 + ... + 13883.

It is an arithmetic number, because the mean of its divisors is an integer number (8739960).

Almost surely, 2^81445406 is an apocalyptic number.

81445406 is a deficient number, since it is larger than the sum of its proper divisors (58393954).

81445406 is a wasteful number, since it uses less digits than its factorization.

81445406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9119.

The product of its (nonzero) digits is 15360, while the sum is 32.

The square root of 81445406 is about 9024.7108540939. The cubic root of 81445406 is about 433.4664917536.

The spelling of 81445406 in words is "eighty-one million, four hundred forty-five thousand, four hundred six".