613726721 has 4 divisors (see below), whose sum is σ = 613955652. Its totient is φ = 613497792.

The previous prime is 613726703. The next prime is 613726723. The reversal of 613726721 is 127627316.

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 410265025 + 203461696 = 20255^2 + 14264^2 .

It is a cyclic number.

It is not a de Polignac number, because 613726721 - 2²⁶ = 546617857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (613726723) 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, 110396 + ... + 115821.

It is an arithmetic number, because the mean of its divisors is an integer number (153488913).

Almost surely, 2^613726721 is an apocalyptic number.

It is an amenable number.

613726721 is a deficient number, since it is larger than the sum of its proper divisors (228931).

613726721 is a wasteful number, since it uses less digits than its factorization.

613726721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228930.

The product of its digits is 21168, while the sum is 35.

The square root of 613726721 is about 24773.5084515698. The cubic root of 613726721 is about 849.8162098594.

The spelling of 613726721 in words is "six hundred thirteen million, seven hundred twenty-six thousand, seven hundred twenty-one".