42091729 has 2 divisors, whose sum is σ = 42091730. Its totient is φ = 42091728.

The previous prime is 42091723. The next prime is 42091747. The reversal of 42091729 is 92719024.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40195600 + 1896129 = 6340^2 + 1377^2 .

It is a cyclic number.

It is not a de Polignac number, because 42091729 - 2⁷ = 42091601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42091694 and 42091703.

It is not a weakly prime, because it can be changed into another prime (42091723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21045864 + 21045865.

It is an arithmetic number, because the mean of its divisors is an integer number (21045865).

Almost surely, 2^42091729 is an apocalyptic number.

It is an amenable number.

42091729 is a deficient number, since it is larger than the sum of its proper divisors (1).

42091729 is an equidigital number, since it uses as much as digits as its factorization.

42091729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 42091729 is about 6487.8138845069. The cubic root of 42091729 is about 347.8555379825.

The spelling of 42091729 in words is "forty-two million, ninety-one thousand, seven hundred twenty-nine".