2661605412157 has 2 divisors, whose sum is σ = 2661605412158. Its totient is φ = 2661605412156.

The previous prime is 2661605412121. The next prime is 2661605412209. The reversal of 2661605412157 is 7512145061662.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2621569003876 + 40036408281 = 1619126^2 + 200091^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661605412157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2661605412457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1330802706078 + 1330802706079.

It is an arithmetic number, because the mean of its divisors is an integer number (1330802706079).

Almost surely, 2^{2661605412157} is an apocalyptic number.

It is an amenable number.

2661605412157 is a deficient number, since it is larger than the sum of its proper divisors (1).

2661605412157 is an equidigital number, since it uses as much as digits as its factorization.

2661605412157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 2661605412157 in words is "two trillion, six hundred sixty-one billion, six hundred five million, four hundred twelve thousand, one hundred fifty-seven".