4020342421 has 2 divisors, whose sum is σ = 4020342422. Its totient is φ = 4020342420.

The previous prime is 4020342409. The next prime is 4020342509. The reversal of 4020342421 is 1242430204.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3498722500 + 521619921 = 59150^2 + 22839^2 .

It is a cyclic number.

It is not a de Polignac number, because 4020342421 - 2¹⁹ = 4019818133 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 4020342392 and 4020342401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4020342721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010171210 + 2010171211.

It is an arithmetic number, because the mean of its divisors is an integer number (2010171211).

Almost surely, 2^4020342421 is an apocalyptic number.

It is an amenable number.

4020342421 is a deficient number, since it is larger than the sum of its proper divisors (1).

4020342421 is an equidigital number, since it uses as much as digits as its factorization.

4020342421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 4020342421 is about 63406.1702123697. The cubic root of 4020342421 is about 1590.0874681257.

Adding to 4020342421 its reverse (1242430204), we get a palindrome (5262772625).

The spelling of 4020342421 in words is "four billion, twenty million, three hundred forty-two thousand, four hundred twenty-one".