613521673 has 4 divisors (see below), whose sum is σ = 613592980. Its totient is φ = 613450368.

The previous prime is 613521661. The next prime is 613521683. The reversal of 613521673 is 376125316.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 451010169 + 162511504 = 21237^2 + 12748^2 .

It is a cyclic number.

It is not a de Polignac number, because 613521673 - 2²¹ = 611424521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (613521683) 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, 20640 + ... + 40657.

It is an arithmetic number, because the mean of its divisors is an integer number (153398245).

Almost surely, 2^613521673 is an apocalyptic number.

It is an amenable number.

613521673 is a deficient number, since it is larger than the sum of its proper divisors (71307).

613521673 is a wasteful number, since it uses less digits than its factorization.

613521673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71306.

The product of its digits is 22680, while the sum is 34.

The square root of 613521673 is about 24769.3696528596. The cubic root of 613521673 is about 849.7215572407.

Adding to 613521673 its reverse (376125316), we get a palindrome (989646989).

The spelling of 613521673 in words is "six hundred thirteen million, five hundred twenty-one thousand, six hundred seventy-three".