42724391 has 2 divisors, whose sum is σ = 42724392. Its totient is φ = 42724390.

The previous prime is 42724387. The next prime is 42724421. The reversal of 42724391 is 19342724.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42724391 - 2² = 42724387 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42754391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21362195 + 21362196.

It is an arithmetic number, because the mean of its divisors is an integer number (21362196).

Almost surely, 2^42724391 is an apocalyptic number.

42724391 is a deficient number, since it is larger than the sum of its proper divisors (1).

42724391 is an equidigital number, since it uses as much as digits as its factorization.

42724391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 32.

The square root of 42724391 is about 6536.3897527611. The cubic root of 42724391 is about 349.5896987881.

The spelling of 42724391 in words is "forty-two million, seven hundred twenty-four thousand, three hundred ninety-one".