2621103078661 has 4 divisors (see below), whose sum is σ = 2635746112800. Its totient is φ = 2606460044524.

The previous prime is 2621103078619. The next prime is 2621103078667. The reversal of 2621103078661 is 1668703011262.

2621103078661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2621103078661 - 2¹⁵ = 2621103045893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2621103078667) 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, 7321516801 + ... + 7321517158.

It is an arithmetic number, because the mean of its divisors is an integer number (658936528200).

Almost surely, 2^{2621103078661} is an apocalyptic number.

It is an amenable number.

2621103078661 is a deficient number, since it is larger than the sum of its proper divisors (14643034139).

2621103078661 is a wasteful number, since it uses less digits than its factorization.

2621103078661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14643034138.

The product of its (nonzero) digits is 145152, while the sum is 43.

The spelling of 2621103078661 in words is "two trillion, six hundred twenty-one billion, one hundred three million, seventy-eight thousand, six hundred sixty-one".