20924221 has 4 divisors (see below), whose sum is σ = 21062944. Its totient is φ = 20785500.

The previous prime is 20924213. The next prime is 20924231. The reversal of 20924221 is 12242902.

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 20924221 - 2³ = 20924213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20924192 and 20924201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20924201) 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, 69135 + ... + 69436.

It is an arithmetic number, because the mean of its divisors is an integer number (5265736).

Almost surely, 2^20924221 is an apocalyptic number.

It is an amenable number.

20924221 is a deficient number, since it is larger than the sum of its proper divisors (138723).

20924221 is a wasteful number, since it uses less digits than its factorization.

20924221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138722.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 20924221 is about 4574.3000557462. The cubic root of 20924221 is about 275.5601628814.

The spelling of 20924221 in words is "twenty million, nine hundred twenty-four thousand, two hundred twenty-one".