2159723661 has 16 divisors (see below), whose sum is σ = 2918548416. Its totient is φ = 1420407936.

The previous prime is 2159723617. The next prime is 2159723677. The reversal of 2159723661 is 1663279512.

It is not a de Polignac number, because 2159723661 - 2¹³ = 2159715469 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2159723611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 176601 + ... + 188433.

It is an arithmetic number, because the mean of its divisors is an integer number (182409276).

Almost surely, 2^2159723661 is an apocalyptic number.

It is an amenable number.

2159723661 is a deficient number, since it is larger than the sum of its proper divisors (758824755).

2159723661 is a wasteful number, since it uses less digits than its factorization.

2159723661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12652.

The product of its digits is 136080, while the sum is 42.

The square root of 2159723661 is about 46472.8271251061. The cubic root of 2159723661 is about 1292.6056862674.

The spelling of 2159723661 in words is "two billion, one hundred fifty-nine million, seven hundred twenty-three thousand, six hundred sixty-one".