81754889 has 2 divisors, whose sum is σ = 81754890. Its totient is φ = 81754888.

The previous prime is 81754879. The next prime is 81754909. The reversal of 81754889 is 98845718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72250000 + 9504889 = 8500^2 + 3083^2 .

It is a cyclic number.

It is not a de Polignac number, because 81754889 - 2⁸ = 81754633 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81754879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40877444 + 40877445.

It is an arithmetic number, because the mean of its divisors is an integer number (40877445).

Almost surely, 2^81754889 is an apocalyptic number.

It is an amenable number.

81754889 is a deficient number, since it is larger than the sum of its proper divisors (1).

81754889 is an equidigital number, since it uses as much as digits as its factorization.

81754889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 645120, while the sum is 50.

The square root of 81754889 is about 9041.8410182883. The cubic root of 81754889 is about 434.0148384147.

The spelling of 81754889 in words is "eighty-one million, seven hundred fifty-four thousand, eight hundred eighty-nine".