81449478 has 24 divisors (see below), whose sum is σ = 192517416. Its totient is φ = 24681600.

The previous prime is 81449437. The next prime is 81449479. The reversal of 81449478 is 87494418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81449479) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 205483 + ... + 205878.

It is an arithmetic number, because the mean of its divisors is an integer number (8021559).

Almost surely, 2^81449478 is an apocalyptic number.

81449478 is an abundant number, since it is smaller than the sum of its proper divisors (111067938).

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

81449478 is a wasteful number, since it uses less digits than its factorization.

81449478 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411380 (or 411377 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 81449478 is about 9024.9364540699. The cubic root of 81449478 is about 433.4737155952.

The spelling of 81449478 in words is "eighty-one million, four hundred forty-nine thousand, four hundred seventy-eight".