2172780638 has 36 divisors (see below), whose sum is σ = 3917694816. Its totient is φ = 901114200.

The previous prime is 2172780593. The next prime is 2172780641. The reversal of 2172780638 is 8360872712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 82643 + ... + 105713.

It is an arithmetic number, because the mean of its divisors is an integer number (108824856).

Almost surely, 2^2172780638 is an apocalyptic number.

2172780638 is a deficient number, since it is larger than the sum of its proper divisors (1744914178).

2172780638 is a wasteful number, since it uses less digits than its factorization.

2172780638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23149 (or 23111 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 44.

The square root of 2172780638 is about 46613.0951343075. The cubic root of 2172780638 is about 1295.2053436247.

The spelling of 2172780638 in words is "two billion, one hundred seventy-two million, seven hundred eighty thousand, six hundred thirty-eight".