42123691 has 2 divisors, whose sum is σ = 42123692. Its totient is φ = 42123690.

The previous prime is 42123677. The next prime is 42123721. The reversal of 42123691 is 19632124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42123691 - 2⁵ = 42123659 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42123091) 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, 21061845 + 21061846.

It is an arithmetic number, because the mean of its divisors is an integer number (21061846).

Almost surely, 2^42123691 is an apocalyptic number.

42123691 is a deficient number, since it is larger than the sum of its proper divisors (1).

42123691 is an equidigital number, since it uses as much as digits as its factorization.

42123691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 28.

The square root of 42123691 is about 6490.2766504980. The cubic root of 42123691 is about 347.9435627639.

The spelling of 42123691 in words is "forty-two million, one hundred twenty-three thousand, six hundred ninety-one".