22728879121 has 9 divisors (see below), whose sum is σ = 24613867281. Its totient is φ = 20978694672.

The previous prime is 22728879091. The next prime is 22728879133. The reversal of 22728879121 is 12197882722.

The square root of 22728879121 is 150761.

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

It can be written as a sum of positive squares in 4 ways, for example, as 36469521 + 22692409600 = 6039^2 + 150640^2 .

It is not a de Polignac number, because 22728879121 - 2⁷ = 22728878993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22728879721) 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, 1954095 + ... + 1965691.

Almost surely, 2^22728879121 is an apocalyptic number.

22728879121 is the 150761-st square number.

22728879121 is the 75381-st centered octagonal number.

It is an amenable number.

22728879121 is a deficient number, since it is larger than the sum of its proper divisors (1884988160).

22728879121 is an frugal number, since it uses more digits than its factorization.

22728879121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23220 (or 11610 counting only the distinct ones).

The product of its digits is 451584, while the sum is 49.

Multiplying 22728879121 by its sum of digits (49), we get a square (1113715076929 = 1055327²).

The spelling of 22728879121 in words is "twenty-two billion, seven hundred twenty-eight million, eight hundred seventy-nine thousand, one hundred twenty-one".