1642021 has 2 divisors, whose sum is σ = 1642022. Its totient is φ = 1642020.

The previous prime is 1641971. The next prime is 1642031. The reversal of 1642021 is 1202461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1079521 + 562500 = 1039^2 + 750^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642021 - 2⁹ = 1641509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1641986 and 1642004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1642031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821010 + 821011.

It is an arithmetic number, because the mean of its divisors is an integer number (821011).

2^1642021 is an apocalyptic number.

It is an amenable number.

1642021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1642021 is an equidigital number, since it uses as much as digits as its factorization.

1642021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 1642021 is about 1281.4136724727. The cubic root of 1642021 is about 117.9757922188.

Adding to 1642021 its reverse (1202461), we get a palindrome (2844482).

The spelling of 1642021 in words is "one million, six hundred forty-two thousand, twenty-one".