22199749378921 has 9 divisors (see below), whose sum is σ = 22470834574461. Its totient is φ = 21931896162732.

The previous prime is 22199749378913. The next prime is 22199749378957. The reversal of 22199749378921 is 12987394799122.

The square root of 22199749378921 is 4711661.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 22199749378921 - 2³ = 22199749378913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22199749378981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 391039480 + ... + 391096246.

Almost surely, 2^{22199749378921} is an apocalyptic number.

22199749378921 is the 4711661-st square number.

22199749378921 is the 2355831-st centered octagonal number.

It is an amenable number.

22199749378921 is a deficient number, since it is larger than the sum of its proper divisors (271085195540).

22199749378921 is an frugal number, since it uses more digits than its factorization.

22199749378921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113700 (or 56850 counting only the distinct ones).

The product of its digits is 246903552, while the sum is 73.

The spelling of 22199749378921 in words is "twenty-two trillion, one hundred ninety-nine billion, seven hundred forty-nine million, three hundred seventy-eight thousand, nine hundred twenty-one".