2660621505613 has 4 divisors (see below), whose sum is σ = 2817128653020. Its totient is φ = 2504114358208.

The previous prime is 2660621505557. The next prime is 2660621505671. The reversal of 2660621505613 is 3165051260662.

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 882551271364 + 1778070234249 = 939442^2 + 1333443^2 .

It is a cyclic number.

It is not a de Polignac number, because 2660621505613 - 2¹³ = 2660621497421 is a prime.

It is a super-2 number, since 2×2660621505613² (a number of 26 digits) contains 22 as substring.

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 2660621505613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2660621535613) 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, 78253573678 + ... + 78253573711.

It is an arithmetic number, because the mean of its divisors is an integer number (704282163255).

Almost surely, 2^{2660621505613} is an apocalyptic number.

It is an amenable number.

2660621505613 is a deficient number, since it is larger than the sum of its proper divisors (156507147407).

2660621505613 is a wasteful number, since it uses less digits than its factorization.

2660621505613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156507147406.

The product of its (nonzero) digits is 388800, while the sum is 43.

The spelling of 2660621505613 in words is "two trillion, six hundred sixty billion, six hundred twenty-one million, five hundred five thousand, six hundred thirteen".