3988021 has 2 divisors, whose sum is σ = 3988022.
Its totient is φ = 3988020.
The previous prime is 3988007. The next prime is 3988027. The reversal of 3988021 is 1208893.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 3478225 + 509796 = 1865^2 + 714^2
It is a cyclic number.
It is not a de Polignac number, because 3988021 - 217 = 3856949 is a prime.
It is a super-2 number, since 2×39880212 = 31808622992882, which contains 22 as substring.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (3988027) 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, 1994010 + 1994011.
It is an arithmetic number, because the mean of its divisors is an integer number (1994011).
Almost surely, 23988021 is an apocalyptic number.
It is an amenable number.
3988021 is a deficient number, since it is larger than the sum of its proper divisors (1).
3988021 is an equidigital number, since it uses as much as digits as its factorization.
3988021 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 3456, while the sum is 31.
The square root of 3988021 is about 1997.0030045045.
The cubic root of 3988021 is about 158.5814844381.
The spelling of 3988021 in words is "three million, nine hundred eighty-eight thousand, twenty-one".