81735889 has 2 divisors, whose sum is σ = 81735890. Its totient is φ = 81735888.

The previous prime is 81735877. The next prime is 81735893. The reversal of 81735889 is 98853718.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70845889 + 10890000 = 8417^2 + 3300^2 .

It is a cyclic number.

It is not a de Polignac number, because 81735889 - 2¹³ = 81727697 is a prime.

It is not a weakly prime, because it can be changed into another prime (81735089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40867944 + 40867945.

It is an arithmetic number, because the mean of its divisors is an integer number (40867945).

Almost surely, 2^81735889 is an apocalyptic number.

It is an amenable number.

81735889 is a deficient number, since it is larger than the sum of its proper divisors (1).

81735889 is an equidigital number, since it uses as much as digits as its factorization.

81735889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 49.

The square root of 81735889 is about 9040.7902862526. The cubic root of 81735889 is about 433.9812138371.

The spelling of 81735889 in words is "eighty-one million, seven hundred thirty-five thousand, eight hundred eighty-nine".