3640729 has 8 divisors (see below), whose sum is σ = 3764232. Its totient is φ = 3519360.

The previous prime is 3640717. The next prime is 3640753. The reversal of 3640729 is 9270463.

It can be written as a sum of positive squares in 4 ways, for example, as 1166400 + 2474329 = 1080^2 + 1573^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3640729 - 2⁵ = 3640697 is a prime.

It is a Duffinian number.

3640729 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3640729.

It is not an unprimeable number, because it can be changed into a prime (3640789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3399 + ... + 4339.

It is an arithmetic number, because the mean of its divisors is an integer number (470529).

Almost surely, 2^3640729 is an apocalyptic number.

It is an amenable number.

3640729 is a deficient number, since it is larger than the sum of its proper divisors (123503).

3640729 is an equidigital number, since it uses as much as digits as its factorization.

3640729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067.

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 3640729 is about 1908.0694431807. The cubic root of 3640729 is about 153.8377021831.

The spelling of 3640729 in words is "three million, six hundred forty thousand, seven hundred twenty-nine".