81440583 has 16 divisors (see below), whose sum is σ = 124323840. Its totient is φ = 46453536.

The previous prime is 81440573. The next prime is 81440617. The reversal of 81440583 is 38504418.

It is not a de Polignac number, because 81440583 - 2¹⁰ = 81439559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81440533) 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, 9553 + ... + 15941.

It is an arithmetic number, because the mean of its divisors is an integer number (7770240).

Almost surely, 2^81440583 is an apocalyptic number.

81440583 is a deficient number, since it is larger than the sum of its proper divisors (42883257).

81440583 is a wasteful number, since it uses less digits than its factorization.

81440583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7006.

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

The square root of 81440583 is about 9024.4436393608. The cubic root of 81440583 is about 433.4579353055.

The spelling of 81440583 in words is "eighty-one million, four hundred forty thousand, five hundred eighty-three".