81988243 has 2 divisors, whose sum is σ = 81988244. Its totient is φ = 81988242.

The previous prime is 81988237. The next prime is 81988303. The reversal of 81988243 is 34288918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81988243 - 2¹³ = 81980051 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81988243.

It is not a weakly prime, because it can be changed into another prime (81988223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40994121 + 40994122.

It is an arithmetic number, because the mean of its divisors is an integer number (40994122).

Almost surely, 2^81988243 is an apocalyptic number.

81988243 is a deficient number, since it is larger than the sum of its proper divisors (1).

81988243 is an equidigital number, since it uses as much as digits as its factorization.

81988243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 43.

The square root of 81988243 is about 9054.7359431405. The cubic root of 81988243 is about 434.4273841418.

The spelling of 81988243 in words is "eighty-one million, nine hundred eighty-eight thousand, two hundred forty-three".