20512403 has 2 divisors, whose sum is σ = 20512404. Its totient is φ = 20512402.

The previous prime is 20512399. The next prime is 20512411. The reversal of 20512403 is 30421502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20512403 - 2² = 20512399 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (20512433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10256201 + 10256202.

It is an arithmetic number, because the mean of its divisors is an integer number (10256202).

Almost surely, 2^20512403 is an apocalyptic number.

20512403 is a deficient number, since it is larger than the sum of its proper divisors (1).

20512403 is an equidigital number, since it uses as much as digits as its factorization.

20512403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20512403 is about 4529.0620441765. The cubic root of 20512403 is about 273.7403680159.

Adding to 20512403 its reverse (30421502), we get a palindrome (50933905).

Subtracting 20512403 from its reverse (30421502), we obtain a palindrome (9909099).

The spelling of 20512403 in words is "twenty million, five hundred twelve thousand, four hundred three".