81440103 has 4 divisors (see below), whose sum is σ = 108586808. Its totient is φ = 54293400.

The previous prime is 81440101. The next prime is 81440123. The reversal of 81440103 is 30104418.

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

It is not a de Polignac number, because 81440103 - 2¹ = 81440101 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81440103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81440101) 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, 13573348 + ... + 13573353.

It is an arithmetic number, because the mean of its divisors is an integer number (27146702).

Almost surely, 2^81440103 is an apocalyptic number.

81440103 is a deficient number, since it is larger than the sum of its proper divisors (27146705).

81440103 is a wasteful number, since it uses less digits than its factorization.

81440103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27146704.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 81440103 is about 9024.4170448844. The cubic root of 81440103 is about 433.4570837227.

The spelling of 81440103 in words is "eighty-one million, four hundred forty thousand, one hundred three".