81573427 has 6 divisors (see below), whose sum is σ = 88331172. Its totient is φ = 75298392.

The previous prime is 81573407. The next prime is 81573449. The reversal of 81573427 is 72437518.

It is not a de Polignac number, because 81573427 - 2⁷ = 81573299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81573407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 241173 + ... + 241510.

It is an arithmetic number, because the mean of its divisors is an integer number (14721862).

Almost surely, 2^81573427 is an apocalyptic number.

81573427 is a deficient number, since it is larger than the sum of its proper divisors (6757745).

81573427 is a wasteful number, since it uses less digits than its factorization.

81573427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 482709 (or 482696 counting only the distinct ones).

The product of its digits is 47040, while the sum is 37.

The square root of 81573427 is about 9031.8008724728. The cubic root of 81573427 is about 433.6934894696.

The spelling of 81573427 in words is "eighty-one million, five hundred seventy-three thousand, four hundred twenty-seven".