81038647 has 2 divisors, whose sum is σ = 81038648. Its totient is φ = 81038646.

The previous prime is 81038641. The next prime is 81038693. The reversal of 81038647 is 74683018.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81038647 - 2¹⁹ = 80514359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81038641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40519323 + 40519324.

It is an arithmetic number, because the mean of its divisors is an integer number (40519324).

Almost surely, 2^81038647 is an apocalyptic number.

81038647 is a deficient number, since it is larger than the sum of its proper divisors (1).

81038647 is an equidigital number, since it uses as much as digits as its factorization.

81038647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 81038647 is about 9002.1467995140. The cubic root of 81038647 is about 432.7436732611.

The spelling of 81038647 in words is "eighty-one million, thirty-eight thousand, six hundred forty-seven".