81971033 has 8 divisors (see below), whose sum is σ = 82684800. Its totient is φ = 81260368.

The previous prime is 81971017. The next prime is 81971039. The reversal of 81971033 is 33017918.

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

It is a cyclic number.

It is not a de Polignac number, because 81971033 - 2⁴ = 81971017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81971039) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 113648 + ... + 114366.

It is an arithmetic number, because the mean of its divisors is an integer number (10335600).

Almost surely, 2^81971033 is an apocalyptic number.

It is an amenable number.

81971033 is a deficient number, since it is larger than the sum of its proper divisors (713767).

81971033 is a wasteful number, since it uses less digits than its factorization.

81971033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 81971033 is about 9053.7855618520. The cubic root of 81971033 is about 434.3969853993.

The spelling of 81971033 in words is "eighty-one million, nine hundred seventy-one thousand, thirty-three".