42021911 has 2 divisors, whose sum is σ = 42021912. Its totient is φ = 42021910.

The previous prime is 42021907. The next prime is 42021913. The reversal of 42021911 is 11912024.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42021911 - 2² = 42021907 is a prime.

It is a Sophie Germain prime.

Together with 42021913, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42021913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21010955 + 21010956.

It is an arithmetic number, because the mean of its divisors is an integer number (21010956).

Almost surely, 2^42021911 is an apocalyptic number.

42021911 is a deficient number, since it is larger than the sum of its proper divisors (1).

42021911 is an equidigital number, since it uses as much as digits as its factorization.

42021911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 42021911 is about 6482.4309483403. The cubic root of 42021911 is about 347.6631009800.

Adding to 42021911 its reverse (11912024), we get a palindrome (53933935).

The spelling of 42021911 in words is "forty-two million, twenty-one thousand, nine hundred eleven".