81030578 has 4 divisors (see below), whose sum is σ = 121545870. Its totient is φ = 40515288.

The previous prime is 81030577. The next prime is 81030613. The reversal of 81030578 is 87503018.

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

It can be written as a sum of positive squares in only one way, i.e., 62047129 + 18983449 = 7877^2 + 4357^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81030577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20257643 + ... + 20257646.

Almost surely, 2^81030578 is an apocalyptic number.

81030578 is a deficient number, since it is larger than the sum of its proper divisors (40515292).

81030578 is a wasteful number, since it uses less digits than its factorization.

81030578 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40515291.

The product of its (nonzero) digits is 6720, while the sum is 32.

The square root of 81030578 is about 9001.6986174833. The cubic root of 81030578 is about 432.7293100540.

The spelling of 81030578 in words is "eighty-one million, thirty thousand, five hundred seventy-eight".