73136521 has 4 divisors (see below), whose sum is σ = 75658500. Its totient is φ = 70614544.

The previous prime is 73136513. The next prime is 73136543. The reversal of 73136521 is 12563137.

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

It can be written as a sum of positive squares in 2 ways, for example, as 32035600 + 41100921 = 5660^2 + 6411^2 .

It is a cyclic number.

It is not a de Polignac number, because 73136521 - 2³ = 73136513 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 73136521.

It is not an unprimeable number, because it can be changed into a prime (73131521) 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, 1260946 + ... + 1261003.

It is an arithmetic number, because the mean of its divisors is an integer number (18914625).

Almost surely, 2^73136521 is an apocalyptic number.

It is an amenable number.

73136521 is a deficient number, since it is larger than the sum of its proper divisors (2521979).

73136521 is a wasteful number, since it uses less digits than its factorization.

73136521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521978.

The product of its digits is 3780, while the sum is 28.

The square root of 73136521 is about 8551.9893007417. The cubic root of 73136521 is about 418.1942905299.

Adding to 73136521 its reverse (12563137), we get a palindrome (85699658).

The spelling of 73136521 in words is "seventy-three million, one hundred thirty-six thousand, five hundred twenty-one".