72137645 has 8 divisors (see below), whose sum is σ = 89550360. Its totient is φ = 55720000.

The previous prime is 72137603. The next prime is 72137669. The reversal of 72137645 is 54673127.

It can be written as a sum of positive squares in 4 ways, for example, as 4338889 + 67798756 = 2083^2 + 8234^2 .

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

It is not a de Polignac number, because 72137645 - 2¹⁰ = 72136621 is a prime.

It is a super-3 number, since 3×72137645³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 248606 + ... + 248895.

It is an arithmetic number, because the mean of its divisors is an integer number (11193795).

Almost surely, 2^72137645 is an apocalyptic number.

It is an amenable number.

72137645 is a deficient number, since it is larger than the sum of its proper divisors (17412715).

72137645 is a wasteful number, since it uses less digits than its factorization.

72137645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497535.

The product of its digits is 35280, while the sum is 35.

The square root of 72137645 is about 8493.3883109157. The cubic root of 72137645 is about 416.2817006100.

The spelling of 72137645 in words is "seventy-two million, one hundred thirty-seven thousand, six hundred forty-five".