81540373 has 8 divisors (see below), whose sum is σ = 84480480. Its totient is φ = 78608880.

The previous prime is 81540367. The next prime is 81540379. The reversal of 81540373 is 37304518.

It is an interprime number because it is at equal distance from previous prime (81540367) and next prime (81540379).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81540373 - 2¹⁷ = 81409301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81540379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21786 + ... + 25252.

It is an arithmetic number, because the mean of its divisors is an integer number (10560060).

Almost surely, 2^81540373 is an apocalyptic number.

It is an amenable number.

81540373 is a deficient number, since it is larger than the sum of its proper divisors (2940107).

81540373 is a wasteful number, since it uses less digits than its factorization.

81540373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4307.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 81540373 is about 9029.9708194434. The cubic root of 81540373 is about 433.6349032289.

The spelling of 81540373 in words is "eighty-one million, five hundred forty thousand, three hundred seventy-three".