2661608215805 has 32 divisors (see below), whose sum is σ = 4216280221440. Its totient is φ = 1561585259520.

The previous prime is 2661608215793. The next prime is 2661608215867. The reversal of 2661608215805 is 5085128061662.

It is not a de Polignac number, because 2661608215805 - 2²⁶ = 2661541106941 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 203324870 + ... + 203337959.

It is an arithmetic number, because the mean of its divisors is an integer number (131758756920).

Almost surely, 2^{2661608215805} is an apocalyptic number.

It is an amenable number.

2661608215805 is a deficient number, since it is larger than the sum of its proper divisors (1554672005635).

2661608215805 is a wasteful number, since it uses less digits than its factorization.

2661608215805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 406662869.

The product of its (nonzero) digits is 1382400, while the sum is 50.

The spelling of 2661608215805 in words is "two trillion, six hundred sixty-one billion, six hundred eight million, two hundred fifteen thousand, eight hundred five".