72313521 has 8 divisors (see below), whose sum is σ = 110192064. Its totient is φ = 41322000.

The previous prime is 72313517. The next prime is 72313523. The reversal of 72313521 is 12531327.

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

It is not a de Polignac number, because 72313521 - 2² = 72313517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72313491 and 72313500.

It is not an unprimeable number, because it can be changed into a prime (72313523) 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, 1721730 + ... + 1721771.

It is an arithmetic number, because the mean of its divisors is an integer number (13774008).

Almost surely, 2^72313521 is an apocalyptic number.

It is an amenable number.

72313521 is a deficient number, since it is larger than the sum of its proper divisors (37878543).

72313521 is a wasteful number, since it uses less digits than its factorization.

72313521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3443511.

The product of its digits is 1260, while the sum is 24.

The square root of 72313521 is about 8503.7357084989. The cubic root of 72313521 is about 416.6197328113.

Adding to 72313521 its reverse (12531327), we get a palindrome (84844848).

The spelling of 72313521 in words is "seventy-two million, three hundred thirteen thousand, five hundred twenty-one".