42365821 has 2 divisors, whose sum is σ = 42365822. Its totient is φ = 42365820.

The previous prime is 42365789. The next prime is 42365837. The reversal of 42365821 is 12856324.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29484900 + 12880921 = 5430^2 + 3589^2 .

It is a cyclic number.

It is not a de Polignac number, because 42365821 - 2⁵ = 42365789 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42365891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21182910 + 21182911.

It is an arithmetic number, because the mean of its divisors is an integer number (21182911).

Almost surely, 2^42365821 is an apocalyptic number.

It is an amenable number.

42365821 is a deficient number, since it is larger than the sum of its proper divisors (1).

42365821 is an equidigital number, since it uses as much as digits as its factorization.

42365821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 31.

The square root of 42365821 is about 6508.9032102191. The cubic root of 42365821 is about 348.6089576679.

The spelling of 42365821 in words is "forty-two million, three hundred sixty-five thousand, eight hundred twenty-one".