82013021 has 4 divisors (see below), whose sum is σ = 82031292. Its totient is φ = 81994752.

The previous prime is 82013003. The next prime is 82013093. The reversal of 82013021 is 12031028.

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

It can be written as a sum of positive squares in 2 ways, for example, as 74200996 + 7812025 = 8614^2 + 2795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-82013021 is a prime.

It is a super-2 number, since 2×82013021² = 13452271227092882, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82013221) 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, 2771 + ... + 13103.

It is an arithmetic number, because the mean of its divisors is an integer number (20507823).

Almost surely, 2^82013021 is an apocalyptic number.

It is an amenable number.

82013021 is a deficient number, since it is larger than the sum of its proper divisors (18271).

82013021 is a wasteful number, since it uses less digits than its factorization.

82013021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18270.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 82013021 is about 9056.1040740486. The cubic root of 82013021 is about 434.4711430888.

Adding to 82013021 its reverse (12031028), we get a palindrome (94044049).

The spelling of 82013021 in words is "eighty-two million, thirteen thousand, twenty-one".