72208639 has 4 divisors (see below), whose sum is σ = 76456224. Its totient is φ = 67961056.

The previous prime is 72208627. The next prime is 72208649. The reversal of 72208639 is 93680227.

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

It is a cyclic number.

It is not a de Polignac number, because 72208639 - 2²¹ = 70111487 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 72208598 and 72208607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72208649) 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, 2123767 + ... + 2123800.

It is an arithmetic number, because the mean of its divisors is an integer number (19114056).

Almost surely, 2^72208639 is an apocalyptic number.

72208639 is a deficient number, since it is larger than the sum of its proper divisors (4247585).

72208639 is a wasteful number, since it uses less digits than its factorization.

72208639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4247584.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 72208639 is about 8497.5666516951. The cubic root of 72208639 is about 416.4182165413.

The spelling of 72208639 in words is "seventy-two million, two hundred eight thousand, six hundred thirty-nine".