81440167 has 4 divisors (see below), whose sum is σ = 81895320. Its totient is φ = 80985016.

The previous prime is 81440159. The next prime is 81440173. The reversal of 81440167 is 76104418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81440167 - 2³ = 81440159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81441167) 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, 227308 + ... + 227665.

It is an arithmetic number, because the mean of its divisors is an integer number (20473830).

Almost surely, 2^81440167 is an apocalyptic number.

81440167 is a deficient number, since it is larger than the sum of its proper divisors (455153).

81440167 is a wasteful number, since it uses less digits than its factorization.

81440167 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455152.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81440167 is about 9024.4205908191. The cubic root of 81440167 is about 433.4571972672.

The spelling of 81440167 in words is "eighty-one million, four hundred forty thousand, one hundred sixty-seven".