81303237 has 8 divisors (see below), whose sum is σ = 120449280. Its totient is φ = 54202140.

The previous prime is 81303203. The next prime is 81303311. The reversal of 81303237 is 73230318.

It is a de Polignac number, because none of the positive numbers 2^k-81303237 is a prime.

It is a super-2 number, since 2×81303237² = 13220432693356338, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 3011231 = 81303237 / (8 + 1 + 3 + 0 + 3 + 2 + 3 + 7).

It is a self number, because there is not a number n which added to its sum of digits gives 81303237.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81303437) 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, 1505589 + ... + 1505642.

It is an arithmetic number, because the mean of its divisors is an integer number (15056160).

Almost surely, 2^81303237 is an apocalyptic number.

It is an amenable number.

81303237 is a deficient number, since it is larger than the sum of its proper divisors (39146043).

81303237 is a wasteful number, since it uses less digits than its factorization.

81303237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3011240 (or 3011234 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 81303237 is about 9016.8307625240. The cubic root of 81303237 is about 433.2141288813.

The spelling of 81303237 in words is "eighty-one million, three hundred three thousand, two hundred thirty-seven".