81027613 has 2 divisors, whose sum is σ = 81027614. Its totient is φ = 81027612.

The previous prime is 81027599. The next prime is 81027641. The reversal of 81027613 is 31672018.

It is an a-pointer prime, because the next prime (81027641) can be obtained adding 81027613 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64689849 + 16337764 = 8043^2 + 4042^2 .

It is a cyclic number.

It is not a de Polignac number, because 81027613 - 2²¹ = 78930461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81027673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40513806 + 40513807.

It is an arithmetic number, because the mean of its divisors is an integer number (40513807).

Almost surely, 2^81027613 is an apocalyptic number.

It is an amenable number.

81027613 is a deficient number, since it is larger than the sum of its proper divisors (1).

81027613 is an equidigital number, since it uses as much as digits as its factorization.

81027613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 81027613 is about 9001.5339248375. The cubic root of 81027613 is about 432.7240319722.

The spelling of 81027613 in words is "eighty-one million, twenty-seven thousand, six hundred thirteen".