20528999 has 2 divisors, whose sum is σ = 20529000. Its totient is φ = 20528998.

The previous prime is 20528993. The next prime is 20529023. The reversal of 20528999 is 99982502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20528999 - 2⁸ = 20528743 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20528993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264499 + 10264500.

It is an arithmetic number, because the mean of its divisors is an integer number (10264500).

Almost surely, 2^20528999 is an apocalyptic number.

20528999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528999 is an equidigital number, since it uses as much as digits as its factorization.

20528999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 20528999 is about 4530.8938411753. The cubic root of 20528999 is about 273.8141732887.

The spelling of 20528999 in words is "twenty million, five hundred twenty-eight thousand, nine hundred ninety-nine".