81381498 has 32 divisors (see below), whose sum is σ = 185283072. Its totient is φ = 23588400.

The previous prime is 81381497. The next prime is 81381539. The reversal of 81381498 is 89418318.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81381497) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25288 + ... + 28323.

It is an arithmetic number, because the mean of its divisors is an integer number (5790096).

Almost surely, 2^81381498 is an apocalyptic number.

81381498 is an abundant number, since it is smaller than the sum of its proper divisors (103901574).

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

81381498 is a wasteful number, since it uses less digits than its factorization.

81381498 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53650.

The product of its digits is 55296, while the sum is 42.

The square root of 81381498 is about 9021.1694363868. The cubic root of 81381498 is about 433.3530856217.

The spelling of 81381498 in words is "eighty-one million, three hundred eighty-one thousand, four hundred ninety-eight".