81327998 has 16 divisors (see below), whose sum is σ = 126058464. Its totient is φ = 39322080.

The previous prime is 81327997. The next prime is 81328057. The reversal of 81327998 is 89972318.

It is a super-2 number, since 2×81327998² = 13228486517376008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81327997) 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, 9068 + ... + 15648.

It is an arithmetic number, because the mean of its divisors is an integer number (7878654).

Almost surely, 2^81327998 is an apocalyptic number.

81327998 is a deficient number, since it is larger than the sum of its proper divisors (44730466).

81327998 is a wasteful number, since it uses less digits than its factorization.

81327998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6787.

The product of its digits is 217728, while the sum is 47.

The square root of 81327998 is about 9018.2037014031. The cubic root of 81327998 is about 433.2581030480.

The spelling of 81327998 in words is "eighty-one million, three hundred twenty-seven thousand, nine hundred ninety-eight".