72101909 has 8 divisors (see below), whose sum is σ = 79141152. Its totient is φ = 65143440.

The previous prime is 72101857. The next prime is 72101951. The reversal of 72101909 is 90910127.

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 72101909 - 2¹² = 72097813 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72101959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18314 + ... + 21899.

It is an arithmetic number, because the mean of its divisors is an integer number (9892644).

Almost surely, 2^72101909 is an apocalyptic number.

It is an amenable number.

72101909 is a deficient number, since it is larger than the sum of its proper divisors (7039243).

72101909 is a wasteful number, since it uses less digits than its factorization.

72101909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40387.

The product of its (nonzero) digits is 1134, while the sum is 29.

The square root of 72101909 is about 8491.2842962652. The cubic root of 72101909 is about 416.2129491742.

It can be divided in two parts, 7210 and 1909, that added together give a palindrome (9119).

The spelling of 72101909 in words is "seventy-two million, one hundred one thousand, nine hundred nine".