2161377703649 has 2 divisors, whose sum is σ = 2161377703650. Its totient is φ = 2161377703648.

The previous prime is 2161377703621. The next prime is 2161377703663. The reversal of 2161377703649 is 9463077731612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1495807273024 + 665570430625 = 1223032^2 + 815825^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161377703649 - 2¹² = 2161377699553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2161377703594 and 2161377703603.

It is not a weakly prime, because it can be changed into another prime (2161377703609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080688851824 + 1080688851825.

It is an arithmetic number, because the mean of its divisors is an integer number (1080688851825).

Almost surely, 2^{2161377703649} is an apocalyptic number.

It is an amenable number.

2161377703649 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161377703649 is an equidigital number, since it uses as much as digits as its factorization.

2161377703649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8001504, while the sum is 56.

The spelling of 2161377703649 in words is "two trillion, one hundred sixty-one billion, three hundred seventy-seven million, seven hundred three thousand, six hundred forty-nine".