42650021 has 2 divisors, whose sum is σ = 42650022. Its totient is φ = 42650020.

The previous prime is 42649993. The next prime is 42650033. The reversal of 42650021 is 12005624.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38925121 + 3724900 = 6239^2 + 1930^2 .

It is a cyclic number.

It is not a de Polignac number, because 42650021 - 2¹⁰ = 42648997 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 42649975 and 42650002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42650051) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21325010 + 21325011.

It is an arithmetic number, because the mean of its divisors is an integer number (21325011).

Almost surely, 2^42650021 is an apocalyptic number.

It is an amenable number.

42650021 is a deficient number, since it is larger than the sum of its proper divisors (1).

42650021 is an equidigital number, since it uses as much as digits as its factorization.

42650021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 42650021 is about 6530.6983546938. The cubic root of 42650021 is about 349.3867383300.

Adding to 42650021 its reverse (12005624), we get a palindrome (54655645).

The spelling of 42650021 in words is "forty-two million, six hundred fifty thousand, twenty-one".