2172787643 has 4 divisors (see below), whose sum is σ = 2339925168. Its totient is φ = 2005650120.

The previous prime is 2172787637. The next prime is 2172787657. The reversal of 2172787643 is 3467872712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2172787643 - 2⁴ = 2172787627 is a prime.

It is a super-2 number, since 2×2172787643² = 9442012283146990898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2172784643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83568743 + ... + 83568768.

It is an arithmetic number, because the mean of its divisors is an integer number (584981292).

Almost surely, 2^2172787643 is an apocalyptic number.

2172787643 is a deficient number, since it is larger than the sum of its proper divisors (167137525).

2172787643 is a wasteful number, since it uses less digits than its factorization.

2172787643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167137524.

The product of its digits is 790272, while the sum is 47.

The square root of 2172787643 is about 46613.1702740760. The cubic root of 2172787643 is about 1295.2067355283.

The spelling of 2172787643 in words is "two billion, one hundred seventy-two million, seven hundred eighty-seven thousand, six hundred forty-three".