2161723776 has 64 divisors (see below), whose sum is σ = 5752718400. Its totient is φ = 719239680.

The previous prime is 2161723763. The next prime is 2161723777. The reversal of 2161723776 is 6773271612.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161723777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 214335 + ... + 224193.

It is an arithmetic number, because the mean of its divisors is an integer number (89886225).

Almost surely, 2^2161723776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161723776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2876359200).

2161723776 is an abundant number, since it is smaller than the sum of its proper divisors (3590994624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161723776 is an equidigital number, since it uses as much as digits as its factorization.

2161723776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10447 (or 10435 counting only the distinct ones).

The product of its digits is 148176, while the sum is 42.

The square root of 2161723776 is about 46494.3413331128. The cubic root of 2161723776 is about 1293.0045895130.

It can be divided in two parts, 216 and 1723776, that multiplied together give a square (372335616 = 19296²).

The spelling of 2161723776 in words is "two billion, one hundred sixty-one million, seven hundred twenty-three thousand, seven hundred seventy-six".