81850237 has 6 divisors (see below), whose sum is σ = 95213598. Its totient is φ = 70157304.

The previous prime is 81850231. The next prime is 81850243. The reversal of 81850237 is 73205818.

It is an interprime number because it is at equal distance from previous prime (81850231) and next prime (81850243).

It can be written as a sum of positive squares in only one way, i.e., 45441081 + 36409156 = 6741^2 + 6034^2 .

It is not a de Polignac number, because 81850237 - 2³ = 81850229 is a prime.

It is a super-2 number, since 2×81850237² = 13398922593912338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81850231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 835158 + ... + 835255.

It is an arithmetic number, because the mean of its divisors is an integer number (15868933).

Almost surely, 2^81850237 is an apocalyptic number.

It is an amenable number.

81850237 is a deficient number, since it is larger than the sum of its proper divisors (13363361).

81850237 is a wasteful number, since it uses less digits than its factorization.

81850237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1670427 (or 1670420 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 81850237 is about 9047.1120806587. The cubic root of 81850237 is about 434.1834985404.

The spelling of 81850237 in words is "eighty-one million, eight hundred fifty thousand, two hundred thirty-seven".