42739391 has 2 divisors, whose sum is σ = 42739392. Its totient is φ = 42739390.

The previous prime is 42739387. The next prime is 42739393. The reversal of 42739391 is 19393724.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 42739391 - 2² = 42739387 is a prime.

Together with 42739393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42739393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21369695 + 21369696.

It is an arithmetic number, because the mean of its divisors is an integer number (21369696).

Almost surely, 2^42739391 is an apocalyptic number.

42739391 is a deficient number, since it is larger than the sum of its proper divisors (1).

42739391 is an equidigital number, since it uses as much as digits as its factorization.

42739391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 42739391 is about 6537.5370744647. The cubic root of 42739391 is about 349.6306061933.

The spelling of 42739391 in words is "forty-two million, seven hundred thirty-nine thousand, three hundred ninety-one".