42640393 has 2 divisors, whose sum is σ = 42640394. Its totient is φ = 42640392.

The previous prime is 42640363. The next prime is 42640417. The reversal of 42640393 is 39304624.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25887744 + 16752649 = 5088^2 + 4093^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42640393 is a prime.

It is not a weakly prime, because it can be changed into another prime (42640343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21320196 + 21320197.

It is an arithmetic number, because the mean of its divisors is an integer number (21320197).

Almost surely, 2^42640393 is an apocalyptic number.

It is an amenable number.

42640393 is a deficient number, since it is larger than the sum of its proper divisors (1).

42640393 is an equidigital number, since it uses as much as digits as its factorization.

42640393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 31.

The square root of 42640393 is about 6529.9611790577. The cubic root of 42640393 is about 349.3604456608.

The spelling of 42640393 in words is "forty-two million, six hundred forty thousand, three hundred ninety-three".