42657691 has 2 divisors, whose sum is σ = 42657692. Its totient is φ = 42657690.

The previous prime is 42657689. The next prime is 42657731. The reversal of 42657691 is 19675624.

It is an a-pointer prime, because the next prime (42657731) can be obtained adding 42657691 to its sum of digits (40).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42657691 - 2¹ = 42657689 is a prime.

Together with 42657689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42657491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21328845 + 21328846.

It is an arithmetic number, because the mean of its divisors is an integer number (21328846).

Almost surely, 2^42657691 is an apocalyptic number.

42657691 is a deficient number, since it is larger than the sum of its proper divisors (1).

42657691 is an equidigital number, since it uses as much as digits as its factorization.

42657691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 40.

The square root of 42657691 is about 6531.2855549271. The cubic root of 42657691 is about 349.4076811541.

The spelling of 42657691 in words is "forty-two million, six hundred fifty-seven thousand, six hundred ninety-one".