81884867 has 4 divisors (see below), whose sum is σ = 81976056. Its totient is φ = 81793680.

The previous prime is 81884863. The next prime is 81884911. The reversal of 81884867 is 76848818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76848818 = 2 ⋅38424409.

It is a cyclic number.

It is not a de Polignac number, because 81884867 - 2² = 81884863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81884863) 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, 44234 + ... + 46047.

It is an arithmetic number, because the mean of its divisors is an integer number (20494014).

Almost surely, 2^81884867 is an apocalyptic number.

81884867 is a deficient number, since it is larger than the sum of its proper divisors (91189).

81884867 is an equidigital number, since it uses as much as digits as its factorization.

81884867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91188.

The product of its digits is 688128, while the sum is 50.

The square root of 81884867 is about 9049.0257486649. The cubic root of 81884867 is about 434.2447227759.

The spelling of 81884867 in words is "eighty-one million, eight hundred eighty-four thousand, eight hundred sixty-seven".