83428021 has 2 divisors, whose sum is σ = 83428022. Its totient is φ = 83428020.

The previous prime is 83428003. The next prime is 83428049. The reversal of 83428021 is 12082438.

It is an a-pointer prime, because the next prime (83428049) can be obtained adding 83428021 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52403121 + 31024900 = 7239^2 + 5570^2 .

It is a cyclic number.

It is not a de Polignac number, because 83428021 - 2¹⁵ = 83395253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (83428001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41714010 + 41714011.

It is an arithmetic number, because the mean of its divisors is an integer number (41714011).

Almost surely, 2^83428021 is an apocalyptic number.

It is an amenable number.

83428021 is a deficient number, since it is larger than the sum of its proper divisors (1).

83428021 is an equidigital number, since it uses as much as digits as its factorization.

83428021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 83428021 is about 9133.8940764605. The cubic root of 83428021 is about 436.9556043409.

The spelling of 83428021 in words is "eighty-three million, four hundred twenty-eight thousand, twenty-one".