72109213 has 4 divisors (see below), whose sum is σ = 78664608. Its totient is φ = 65553820.

The previous prime is 72109187. The next prime is 72109217. The reversal of 72109213 is 31290127.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31290127 = 11 ⋅2844557.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72109213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72109217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3277681 + ... + 3277702.

It is an arithmetic number, because the mean of its divisors is an integer number (19666152).

Almost surely, 2^72109213 is an apocalyptic number.

It is an amenable number.

72109213 is a deficient number, since it is larger than the sum of its proper divisors (6555395).

72109213 is a wasteful number, since it uses less digits than its factorization.

72109213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6555394.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 72109213 is about 8491.7143734348. The cubic root of 72109213 is about 416.2270029710.

The spelling of 72109213 in words is "seventy-two million, one hundred nine thousand, two hundred thirteen".