81427621 has 8 divisors (see below), whose sum is σ = 91893600. Its totient is φ = 71472240.

The previous prime is 81427589. The next prime is 81427627. The reversal of 81427621 is 12672418.

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

It is not a de Polignac number, because 81427621 - 2⁵ = 81427589 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 (81427627) 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, 127311 + ... + 127948.

It is an arithmetic number, because the mean of its divisors is an integer number (11486700).

Almost surely, 2^81427621 is an apocalyptic number.

It is an amenable number.

81427621 is a deficient number, since it is larger than the sum of its proper divisors (10465979).

81427621 is a wasteful number, since it uses less digits than its factorization.

81427621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255299.

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

The square root of 81427621 is about 9023.7254501675. The cubic root of 81427621 is about 433.4349378447.

The spelling of 81427621 in words is "eighty-one million, four hundred twenty-seven thousand, six hundred twenty-one".