81234989 has 8 divisors (see below), whose sum is σ = 89742720. Its totient is φ = 72914400.

The previous prime is 81234983. The next prime is 81234991. The reversal of 81234989 is 98943218.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81234989 - 2⁸ = 81234733 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81234983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45872 + ... + 47609.

It is an arithmetic number, because the mean of its divisors is an integer number (11217840).

Almost surely, 2^81234989 is an apocalyptic number.

It is an amenable number.

81234989 is a deficient number, since it is larger than the sum of its proper divisors (8507731).

81234989 is a wasteful number, since it uses less digits than its factorization.

81234989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93571.

The product of its digits is 124416, while the sum is 44.

The square root of 81234989 is about 9013.0454897332. The cubic root of 81234989 is about 433.0928779708.

The spelling of 81234989 in words is "eighty-one million, two hundred thirty-four thousand, nine hundred eighty-nine".