20505430 has 32 divisors (see below), whose sum is σ = 40601088. Its totient is φ = 7394400.

The previous prime is 20505409. The next prime is 20505431. The reversal of 20505430 is 3450502.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20505398 and 20505407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13699 + ... + 15121.

It is an arithmetic number, because the mean of its divisors is an integer number (1268784).

Almost surely, 2^20505430 is an apocalyptic number.

20505430 is a deficient number, since it is larger than the sum of its proper divisors (20095658).

20505430 is a wasteful number, since it uses less digits than its factorization.

20505430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1572.

The product of its (nonzero) digits is 600, while the sum is 19.

The square root of 20505430 is about 4528.2921725525. The cubic root of 20505430 is about 273.7093460058.

Adding to 20505430 its reverse (3450502), we get a palindrome (23955932).

The spelling of 20505430 in words is "twenty million, five hundred five thousand, four hundred thirty".