81457445 has 16 divisors (see below), whose sum is σ = 99392832. Its totient is φ = 64078080.

The previous prime is 81457393. The next prime is 81457463. The reversal of 81457445 is 54475418.

It is not a de Polignac number, because 81457445 - 2⁶ = 81457381 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81457399 and 81457408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 137069 + ... + 137661.

It is an arithmetic number, because the mean of its divisors is an integer number (6212052).

Almost surely, 2^81457445 is an apocalyptic number.

It is an amenable number.

81457445 is a deficient number, since it is larger than the sum of its proper divisors (17935387).

81457445 is a wasteful number, since it uses less digits than its factorization.

81457445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1012.

The product of its digits is 89600, while the sum is 38.

The square root of 81457445 is about 9025.3778314262. The cubic root of 81457445 is about 433.4878485792.

The spelling of 81457445 in words is "eighty-one million, four hundred fifty-seven thousand, four hundred forty-five".