82281021 has 4 divisors (see below), whose sum is σ = 109708032. Its totient is φ = 54854012.

The previous prime is 82281019. The next prime is 82281041. The reversal of 82281021 is 12018228.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 82281021 - 2¹ = 82281019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 82280982 and 82281000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82281041) 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, 13713501 + ... + 13713506.

It is an arithmetic number, because the mean of its divisors is an integer number (27427008).

Almost surely, 2^82281021 is an apocalyptic number.

It is an amenable number.

82281021 is a deficient number, since it is larger than the sum of its proper divisors (27427011).

82281021 is a wasteful number, since it uses less digits than its factorization.

82281021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27427010.

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 82281021 is about 9070.8886554736. Note that the first 3 decimals coincide. The cubic root of 82281021 is about 434.9438796672.

Adding to 82281021 its reverse (12018228), we get a palindrome (94299249).

The spelling of 82281021 in words is "eighty-two million, two hundred eighty-one thousand, twenty-one".