22129921 has 4 divisors (see below), whose sum is σ = 24141744. Its totient is φ = 20118100.

The previous prime is 22129901. The next prime is 22129931. The reversal of 22129921 is 12992122.

It is the 1921-st star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 22129921 - 2⁹ = 22129409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22129921.

It is not an unprimeable number, because it can be changed into a prime (22129901) 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, 1005895 + ... + 1005916.

It is an arithmetic number, because the mean of its divisors is an integer number (6035436).

Almost surely, 2^22129921 is an apocalyptic number.

It is an amenable number.

22129921 is a deficient number, since it is larger than the sum of its proper divisors (2011823).

22129921 is a wasteful number, since it uses less digits than its factorization.

22129921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2011822.

The product of its digits is 1296, while the sum is 28.

The square root of 22129921 is about 4704.2449978716. The cubic root of 22129921 is about 280.7544322680.

The spelling of 22129921 in words is "twenty-two million, one hundred twenty-nine thousand, nine hundred twenty-one".