42790409 has 2 divisors, whose sum is σ = 42790410. Its totient is φ = 42790408.

The previous prime is 42790403. The next prime is 42790417. The reversal of 42790409 is 90409724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34105600 + 8684809 = 5840^2 + 2947^2 .

It is a cyclic number.

It is not a de Polignac number, because 42790409 - 2⁴ = 42790393 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (42790403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21395204 + 21395205.

It is an arithmetic number, because the mean of its divisors is an integer number (21395205).

Almost surely, 2^42790409 is an apocalyptic number.

It is an amenable number.

42790409 is a deficient number, since it is larger than the sum of its proper divisors (1).

42790409 is an equidigital number, since it uses as much as digits as its factorization.

42790409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 42790409 is about 6541.4378388853. The cubic root of 42790409 is about 349.7696688630.

The spelling of 42790409 in words is "forty-two million, seven hundred ninety thousand, four hundred nine".