83980021 has 2 divisors, whose sum is σ = 83980022. Its totient is φ = 83980020.

The previous prime is 83979997. The next prime is 83980033. The reversal of 83980021 is 12008938.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61074225 + 22905796 = 7815^2 + 4786^2 .

It is a cyclic number.

It is not a de Polignac number, because 83980021 - 2¹¹ = 83977973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83980621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41990010 + 41990011.

It is an arithmetic number, because the mean of its divisors is an integer number (41990011).

Almost surely, 2^83980021 is an apocalyptic number.

It is an amenable number.

83980021 is a deficient number, since it is larger than the sum of its proper divisors (1).

83980021 is an equidigital number, since it uses as much as digits as its factorization.

83980021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 83980021 is about 9164.0613812872. The cubic root of 83980021 is about 437.9171896432.

Adding to 83980021 its reverse (12008938), we get a palindrome (95988959).

The spelling of 83980021 in words is "eighty-three million, nine hundred eighty thousand, twenty-one".