42097691 has 2 divisors, whose sum is σ = 42097692. Its totient is φ = 42097690.

The previous prime is 42097651. The next prime is 42097697. The reversal of 42097691 is 19679024.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42097691 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (42097697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21048845 + 21048846.

It is an arithmetic number, because the mean of its divisors is an integer number (21048846).

Almost surely, 2^42097691 is an apocalyptic number.

42097691 is a deficient number, since it is larger than the sum of its proper divisors (1).

42097691 is an equidigital number, since it uses as much as digits as its factorization.

42097691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 38.

The square root of 42097691 is about 6488.2733450433. The cubic root of 42097691 is about 347.8719609778.

The spelling of 42097691 in words is "forty-two million, ninety-seven thousand, six hundred ninety-one".