81540438 has 32 divisors (see below), whose sum is σ = 196189440. Its totient is φ = 22070880.

The previous prime is 81540421. The next prime is 81540479. The reversal of 81540438 is 83404518.

It is a junction number, because it is equal to n+sod(n) for n = 81540399 and 81540408.

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, 50293 + ... + 51888.

It is an arithmetic number, because the mean of its divisors is an integer number (6130920).

Almost surely, 2^81540438 is an apocalyptic number.

81540438 is an abundant number, since it is smaller than the sum of its proper divisors (114649002).

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

81540438 is a wasteful number, since it uses less digits than its factorization.

81540438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102212.

The product of its (nonzero) digits is 15360, while the sum is 33.

The square root of 81540438 is about 9029.9744185684. The cubic root of 81540438 is about 433.6350184530.

The spelling of 81540438 in words is "eighty-one million, five hundred forty thousand, four hundred thirty-eight".