81421967 has 8 divisors (see below), whose sum is σ = 88943232. Its totient is φ = 73920600.

The previous prime is 81421961. The next prime is 81421981. The reversal of 81421967 is 76912418.

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 81421967 - 2²² = 77227663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81421967.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81421961) 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, 4358 + ... + 13484.

It is an arithmetic number, because the mean of its divisors is an integer number (11117904).

Almost surely, 2^81421967 is an apocalyptic number.

81421967 is a deficient number, since it is larger than the sum of its proper divisors (7521265).

81421967 is a wasteful number, since it uses less digits than its factorization.

81421967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9949.

The product of its digits is 24192, while the sum is 38.

The square root of 81421967 is about 9023.4121594882. The cubic root of 81421967 is about 433.4249056311.

The spelling of 81421967 in words is "eighty-one million, four hundred twenty-one thousand, nine hundred sixty-seven".