81840007 has 2 divisors, whose sum is σ = 81840008. Its totient is φ = 81840006.

The previous prime is 81839987. The next prime is 81840013. The reversal of 81840007 is 70004818.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81840007 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81840047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40920003 + 40920004.

It is an arithmetic number, because the mean of its divisors is an integer number (40920004).

Almost surely, 2^81840007 is an apocalyptic number.

81840007 is a deficient number, since it is larger than the sum of its proper divisors (1).

81840007 is an equidigital number, since it uses as much as digits as its factorization.

81840007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 81840007 is about 9046.5466892069. The cubic root of 81840007 is about 434.1654090703.

The spelling of 81840007 in words is "eighty-one million, eight hundred forty thousand, seven".