72109729 has 4 divisors (see below), whose sum is σ = 72161280. Its totient is φ = 72058180.

The previous prime is 72109727. The next prime is 72109759. The reversal of 72109729 is 92790127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72109729 - 2¹ = 72109727 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72109727) 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, 23617 + ... + 26494.

It is an arithmetic number, because the mean of its divisors is an integer number (18040320).

Almost surely, 2^72109729 is an apocalyptic number.

It is an amenable number.

72109729 is a deficient number, since it is larger than the sum of its proper divisors (51551).

72109729 is a wasteful number, since it uses less digits than its factorization.

72109729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51550.

The product of its (nonzero) digits is 15876, while the sum is 37.

The square root of 72109729 is about 8491.7447559380. The cubic root of 72109729 is about 416.2279957827.

It can be divided in two parts, 7210 and 9729, that multiplied together give a triangular number (70146090 = T₁₁₈₄₄).

The spelling of 72109729 in words is "seventy-two million, one hundred nine thousand, seven hundred twenty-nine".