40297729 has 4 divisors (see below), whose sum is σ = 40502484. Its totient is φ = 40092976.

The previous prime is 40297723. The next prime is 40297781. The reversal of 40297729 is 92779204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39438400 + 859329 = 6280^2 + 927^2 .

It is a cyclic number.

It is not a de Polignac number, because 40297729 - 2²³ = 31909121 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40297691 and 40297700.

It is not an unprimeable number, because it can be changed into a prime (40297723) 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 in 3 ways as a sum of consecutive naturals, for example, 102082 + ... + 102475.

It is an arithmetic number, because the mean of its divisors is an integer number (10125621).

Almost surely, 2^40297729 is an apocalyptic number.

It is an amenable number.

40297729 is a deficient number, since it is larger than the sum of its proper divisors (204755).

40297729 is a wasteful number, since it uses less digits than its factorization.

40297729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204754.

The product of its (nonzero) digits is 63504, while the sum is 40.

The square root of 40297729 is about 6348.0492279125. The cubic root of 40297729 is about 342.8416084810.

The spelling of 40297729 in words is "forty million, two hundred ninety-seven thousand, seven hundred twenty-nine".