20434421 has 12 divisors (see below), whose sum is σ = 24011820. Its totient is φ = 17337600.

The previous prime is 20434411. The next prime is 20434457. The reversal of 20434421 is 12443402.

It can be written as a sum of positive squares in 2 ways, for example, as 16313521 + 4120900 = 4039^2 + 2030^2 .

It is not a de Polignac number, because 20434421 - 2¹⁰ = 20433397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20434393 and 20434402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20434411) 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 11 ways as a sum of consecutive naturals, for example, 2885 + ... + 7013.

It is an arithmetic number, because the mean of its divisors is an integer number (2000985).

Almost surely, 2^20434421 is an apocalyptic number.

It is an amenable number.

20434421 is a deficient number, since it is larger than the sum of its proper divisors (3577399).

20434421 is a wasteful number, since it uses less digits than its factorization.

20434421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244 (or 4237 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 20434421 is about 4520.4447790013. Note that the first 3 decimals coincide. The cubic root of 20434421 is about 273.3930345829.

Adding to 20434421 its reverse (12443402), we get a palindrome (32877823).

The spelling of 20434421 in words is "twenty million, four hundred thirty-four thousand, four hundred twenty-one".