81938143 has 12 divisors (see below), whose sum is σ = 95931912. Its totient is φ = 69778800.

The previous prime is 81938141. The next prime is 81938173. The reversal of 81938143 is 34183918.

It is not a de Polignac number, because 81938143 - 2¹ = 81938141 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 (81938141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2368 + ... + 13018.

It is an arithmetic number, because the mean of its divisors is an integer number (7994326).

Almost surely, 2^81938143 is an apocalyptic number.

81938143 is a deficient number, since it is larger than the sum of its proper divisors (13993769).

81938143 is a wasteful number, since it uses less digits than its factorization.

81938143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10822 (or 10815 counting only the distinct ones).

The product of its digits is 20736, while the sum is 37.

The square root of 81938143 is about 9051.9690123199. The cubic root of 81938143 is about 434.3388785794.

The spelling of 81938143 in words is "eighty-one million, nine hundred thirty-eight thousand, one hundred forty-three".