2172723261 has 8 divisors (see below), whose sum is σ = 2897181984. Its totient is φ = 1448373360.

The previous prime is 2172723251. The next prime is 2172723263. The reversal of 2172723261 is 1623272712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2172723261 - 2⁵ = 2172723229 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2172723263) 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, 54091 + ... + 85271.

It is an arithmetic number, because the mean of its divisors is an integer number (362147748).

Almost surely, 2^2172723261 is an apocalyptic number.

It is an amenable number.

2172723261 is a deficient number, since it is larger than the sum of its proper divisors (724458723).

2172723261 is a wasteful number, since it uses less digits than its factorization.

2172723261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54411.

The product of its digits is 14112, while the sum is 33.

The square root of 2172723261 is about 46612.4796701484. The cubic root of 2172723261 is about 1295.1939426193.

Adding to 2172723261 its reverse (1623272712), we get a palindrome (3795995973).

The spelling of 2172723261 in words is "two billion, one hundred seventy-two million, seven hundred twenty-three thousand, two hundred sixty-one".