2161377703621 has 2 divisors, whose sum is σ = 2161377703622. Its totient is φ = 2161377703620.

The previous prime is 2161377703609. The next prime is 2161377703649. The reversal of 2161377703621 is 1263077731612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2130756203521 + 30621500100 = 1459711^2 + 174990^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161377703621 - 2⁹ = 2161377703109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161377703601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080688851810 + 1080688851811.

It is an arithmetic number, because the mean of its divisors is an integer number (1080688851811).

Almost surely, 2^{2161377703621} is an apocalyptic number.

It is an amenable number.

2161377703621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161377703621 is an equidigital number, since it uses as much as digits as its factorization.

2161377703621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 444528, while the sum is 46.

The spelling of 2161377703621 in words is "two trillion, one hundred sixty-one billion, three hundred seventy-seven million, seven hundred three thousand, six hundred twenty-one".