81234700409 has 2 divisors, whose sum is σ = 81234700410. Its totient is φ = 81234700408.

The previous prime is 81234700403. The next prime is 81234700433. The reversal of 81234700409 is 90400743218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76984051600 + 4250648809 = 277460^2 + 65197^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81234700409 is a prime.

It is not a weakly prime, because it can be changed into another prime (81234700403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40617350204 + 40617350205.

It is an arithmetic number, because the mean of its divisors is an integer number (40617350205).

Almost surely, 2^81234700409 is an apocalyptic number.

It is an amenable number.

81234700409 is a deficient number, since it is larger than the sum of its proper divisors (1).

81234700409 is an equidigital number, since it uses as much as digits as its factorization.

81234700409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 38.

The spelling of 81234700409 in words is "eighty-one billion, two hundred thirty-four million, seven hundred thousand, four hundred nine".