72335521 has 4 divisors (see below), whose sum is σ = 74099844. Its totient is φ = 70571200.

The previous prime is 72335509. The next prime is 72335533. The reversal of 72335521 is 12553327.

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

It is an interprime number because it is at equal distance from previous prime (72335509) and next prime (72335533).

It can be written as a sum of positive squares in 2 ways, for example, as 8910225 + 63425296 = 2985^2 + 7964^2 .

It is a cyclic number.

It is not a de Polignac number, because 72335521 - 2²¹ = 70238369 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72335521.

It is not an unprimeable number, because it can be changed into a prime (72335321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 882100 + ... + 882181.

It is an arithmetic number, because the mean of its divisors is an integer number (18524961).

Almost surely, 2^72335521 is an apocalyptic number.

It is an amenable number.

72335521 is a deficient number, since it is larger than the sum of its proper divisors (1764323).

72335521 is a wasteful number, since it uses less digits than its factorization.

72335521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1764322.

The product of its digits is 6300, while the sum is 28.

The square root of 72335521 is about 8505.0291592681. The cubic root of 72335521 is about 416.6619780450.

Adding to 72335521 its reverse (12553327), we get a palindrome (84888848).

The spelling of 72335521 in words is "seventy-two million, three hundred thirty-five thousand, five hundred twenty-one".