42021405004021 has 2 divisors, whose sum is σ = 42021405004022. Its totient is φ = 42021405004020.

The previous prime is 42021405004013. The next prime is 42021405004057. The reversal of 42021405004021 is 12040050412024.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31130942999121 + 10890462004900 = 5579511^2 + 3300070^2 .

It is a cyclic number.

It is not a de Polignac number, because 42021405004021 - 2³ = 42021405004013 is a prime.

It is a super-2 number, since 2×42021405004021² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42021405004121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21010702502010 + 21010702502011.

It is an arithmetic number, because the mean of its divisors is an integer number (21010702502011).

Almost surely, 2^{42021405004021} is an apocalyptic number.

It is an amenable number.

42021405004021 is a deficient number, since it is larger than the sum of its proper divisors (1).

42021405004021 is an equidigital number, since it uses as much as digits as its factorization.

42021405004021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 25.

Adding to 42021405004021 its reverse (12040050412024), we get a palindrome (54061455416045).

The spelling of 42021405004021 in words is "forty-two trillion, twenty-one billion, four hundred five million, four thousand, twenty-one".