81447530 has 8 divisors (see below), whose sum is σ = 146605572. Its totient is φ = 32579008.

The previous prime is 81447529. The next prime is 81447533. The reversal of 81447530 is 3574418.

It can be written as a sum of positive squares in 2 ways, for example, as 66601921 + 14845609 = 8161^2 + 3853^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (81447533) 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, 4072367 + ... + 4072386.

Almost surely, 2^81447530 is an apocalyptic number.

81447530 is a deficient number, since it is larger than the sum of its proper divisors (65158042).

81447530 is a wasteful number, since it uses less digits than its factorization.

81447530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8144760.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 81447530 is about 9024.8285302270. The cubic root of 81447530 is about 433.4702598189.

The spelling of 81447530 in words is "eighty-one million, four hundred forty-seven thousand, five hundred thirty".