42021641 has 2 divisors, whose sum is σ = 42021642. Its totient is φ = 42021640.

The previous prime is 42021613. The next prime is 42021689. The reversal of 42021641 is 14612024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 38180041 + 3841600 = 6179^2 + 1960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42021641 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42021691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21010820 + 21010821.

It is an arithmetic number, because the mean of its divisors is an integer number (21010821).

Almost surely, 2^42021641 is an apocalyptic number.

It is an amenable number.

42021641 is a deficient number, since it is larger than the sum of its proper divisors (1).

42021641 is an equidigital number, since it uses as much as digits as its factorization.

42021641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 42021641 is about 6482.4101227861. The cubic root of 42021641 is about 347.6623563745.

Adding to 42021641 its reverse (14612024), we get a palindrome (56633665).

The spelling of 42021641 in words is "forty-two million, twenty-one thousand, six hundred forty-one".