81031403 has 4 divisors (see below), whose sum is σ = 81115320. Its totient is φ = 80947488.

The previous prime is 81031381. The next prime is 81031411. The reversal of 81031403 is 30413018.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30413018 = 2 ⋅15206509.

It is a cyclic number.

It is not a de Polignac number, because 81031403 - 2⁶ = 81031339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81031453) 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, 40493 + ... + 42446.

It is an arithmetic number, because the mean of its divisors is an integer number (20278830).

Almost surely, 2^81031403 is an apocalyptic number.

81031403 is a deficient number, since it is larger than the sum of its proper divisors (83917).

81031403 is an equidigital number, since it uses as much as digits as its factorization.

81031403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83916.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 81031403 is about 9001.7444420512. The cubic root of 81031403 is about 432.7307786373.

The spelling of 81031403 in words is "eighty-one million, thirty-one thousand, four hundred three".