81238205 has 16 divisors (see below), whose sum is σ = 103230720. Its totient is φ = 61201728.

The previous prime is 81238163. The next prime is 81238229. The reversal of 81238205 is 50283218.

It is a cyclic number.

It is not a de Polignac number, because 81238205 - 2¹⁴ = 81221821 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13964 + ... + 18906.

It is an arithmetic number, because the mean of its divisors is an integer number (6451920).

Almost surely, 2^81238205 is an apocalyptic number.

It is an amenable number.

81238205 is a deficient number, since it is larger than the sum of its proper divisors (21992515).

81238205 is a wasteful number, since it uses less digits than its factorization.

81238205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5140.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 81238205 is about 9013.2238960319. The cubic root of 81238205 is about 433.0985931121.

The spelling of 81238205 in words is "eighty-one million, two hundred thirty-eight thousand, two hundred five".