613645666405 has 4 divisors (see below), whose sum is σ = 736374799692. Its totient is φ = 490916533120.

The previous prime is 613645666373. The next prime is 613645666411. The reversal of 613645666405 is 504666546316.

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 142323598564 + 471322067841 = 377258^2 + 686529^2 .

It is not a de Polignac number, because 613645666405 - 2⁵ = 613645666373 is a prime.

It is a super-2 number, since 2×613645666405² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61364566636 + ... + 61364566645.

It is an arithmetic number, because the mean of its divisors is an integer number (184093699923).

Almost surely, 2^613645666405 is an apocalyptic number.

It is an amenable number.

613645666405 is a deficient number, since it is larger than the sum of its proper divisors (122729133287).

613645666405 is a wasteful number, since it uses less digits than its factorization.

613645666405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122729133286.

The product of its (nonzero) digits is 9331200, while the sum is 52.

The spelling of 613645666405 in words is "six hundred thirteen billion, six hundred forty-five million, six hundred sixty-six thousand, four hundred five".