42438691 has 2 divisors, whose sum is σ = 42438692. Its totient is φ = 42438690.

The previous prime is 42438689. The next prime is 42438709. The reversal of 42438691 is 19683424.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42438691 - 2¹ = 42438689 is a prime.

Together with 42438689, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 42438691.

It is not a weakly prime, because it can be changed into another prime (42438601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21219345 + 21219346.

It is an arithmetic number, because the mean of its divisors is an integer number (21219346).

Almost surely, 2^42438691 is an apocalyptic number.

42438691 is a deficient number, since it is larger than the sum of its proper divisors (1).

42438691 is an equidigital number, since it uses as much as digits as its factorization.

42438691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 37.

The square root of 42438691 is about 6514.4985225265. The cubic root of 42438691 is about 348.8087144799.

The spelling of 42438691 in words is "forty-two million, four hundred thirty-eight thousand, six hundred ninety-one".