81283237 has 12 divisors (see below), whose sum is σ = 94228320. Its totient is φ = 68685408.

The previous prime is 81283231. The next prime is 81283243. The reversal of 81283237 is 73238218.

81283237 = 1019² + 1020² + ... + 1091².

It is an interprime number because it is at equal distance from previous prime (81283231) and next prime (81283243).

It is not a de Polignac number, because 81283237 - 2³ = 81283229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81283231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36214 + ... + 38392.

It is an arithmetic number, because the mean of its divisors is an integer number (7852360).

Almost surely, 2^81283237 is an apocalyptic number.

It is an amenable number.

81283237 is a deficient number, since it is larger than the sum of its proper divisors (12945083).

81283237 is an equidigital number, since it uses as much as digits as its factorization.

81283237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2332 (or 2259 counting only the distinct ones).

The product of its digits is 16128, while the sum is 34.

The square root of 81283237 is about 9015.7216571942. The cubic root of 81283237 is about 433.1786034687.

The spelling of 81283237 in words is "eighty-one million, two hundred eighty-three thousand, two hundred thirty-seven".