81354387 has 4 divisors (see below), whose sum is σ = 108472520. Its totient is φ = 54236256.

The previous prime is 81354353. The next prime is 81354397. The reversal of 81354387 is 78345318.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81354387 - 2¹⁵ = 81321619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81354307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13559062 + ... + 13559067.

It is an arithmetic number, because the mean of its divisors is an integer number (27118130).

Almost surely, 2^81354387 is an apocalyptic number.

81354387 is a deficient number, since it is larger than the sum of its proper divisors (27118133).

81354387 is a wasteful number, since it uses less digits than its factorization.

81354387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27118132.

The product of its digits is 80640, while the sum is 39.

The square root of 81354387 is about 9019.6666789854. Note that the first 4 decimals coincide. The cubic root of 81354387 is about 433.3049586286.

The spelling of 81354387 in words is "eighty-one million, three hundred fifty-four thousand, three hundred eighty-seven".