81210007 has 2 divisors, whose sum is σ = 81210008. Its totient is φ = 81210006.

The previous prime is 81209993. The next prime is 81210067. The reversal of 81210007 is 70001218.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81210007 - 2¹⁹ = 80685719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81210067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40605003 + 40605004.

It is an arithmetic number, because the mean of its divisors is an integer number (40605004).

Almost surely, 2^81210007 is an apocalyptic number.

81210007 is a deficient number, since it is larger than the sum of its proper divisors (1).

81210007 is an equidigital number, since it uses as much as digits as its factorization.

81210007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 81210007 is about 9011.6595031104. The cubic root of 81210007 is about 433.0484774167.

The spelling of 81210007 in words is "eighty-one million, two hundred ten thousand, seven".