81030643 has 4 divisors (see below), whose sum is σ = 81378648. Its totient is φ = 80682640.

The previous prime is 81030641. The next prime is 81030661. The reversal of 81030643 is 34603018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81030643 - 2¹ = 81030641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81030641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173653 + ... + 174118.

It is an arithmetic number, because the mean of its divisors is an integer number (20344662).

Almost surely, 2^81030643 is an apocalyptic number.

81030643 is a deficient number, since it is larger than the sum of its proper divisors (348005).

81030643 is a wasteful number, since it uses less digits than its factorization.

81030643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348004.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 81030643 is about 9001.7022279122. The cubic root of 81030643 is about 432.7294257609.

The spelling of 81030643 in words is "eighty-one million, thirty thousand, six hundred forty-three".