1661501782159 has 2 divisors, whose sum is σ = 1661501782160. Its totient is φ = 1661501782158.

The previous prime is 1661501782153. The next prime is 1661501782169. The reversal of 1661501782159 is 9512871051661.

It is a weak prime.

It is an emirp because it is prime and its reverse (9512871051661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661501782159 - 2¹¹ = 1661501780111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661501782153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830750891079 + 830750891080.

It is an arithmetic number, because the mean of its divisors is an integer number (830750891080).

Almost surely, 2^{1661501782159} is an apocalyptic number.

1661501782159 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661501782159 is an equidigital number, since it uses as much as digits as its factorization.

1661501782159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 907200, while the sum is 52.

The spelling of 1661501782159 in words is "one trillion, six hundred sixty-one billion, five hundred one million, seven hundred eighty-two thousand, one hundred fifty-nine".