82880021 has 6 divisors (see below), whose sum is σ = 96411510. Its totient is φ = 71039976.

The previous prime is 82880011. The next prime is 82880027. The reversal of 82880021 is 12008828.

It can be written as a sum of positive squares in only one way, i.e., 78411025 + 4468996 = 8855^2 + 2114^2 .

It is not a de Polignac number, because 82880021 - 2¹⁴ = 82863637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82880027) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 845666 + ... + 845763.

It is an arithmetic number, because the mean of its divisors is an integer number (16068585).

Almost surely, 2^82880021 is an apocalyptic number.

It is an amenable number.

82880021 is a deficient number, since it is larger than the sum of its proper divisors (13531489).

82880021 is a wasteful number, since it uses less digits than its factorization.

82880021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1691443 (or 1691436 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 82880021 is about 9103.8464947515. The cubic root of 82880021 is about 435.9967823038.

Adding to 82880021 its reverse (12008828), we get a palindrome (94888849).

The spelling of 82880021 in words is "eighty-two million, eight hundred eighty thousand, twenty-one".