20530999 has 4 divisors (see below), whose sum is σ = 20820240. Its totient is φ = 20241760.

The previous prime is 20530987. The next prime is 20531023. The reversal of 20530999 is 99903502.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20530999 - 2⁷ = 20530871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20530919) 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, 144514 + ... + 144655.

It is an arithmetic number, because the mean of its divisors is an integer number (5205060).

Almost surely, 2^20530999 is an apocalyptic number.

20530999 is a deficient number, since it is larger than the sum of its proper divisors (289241).

20530999 is an equidigital number, since it uses as much as digits as its factorization.

20530999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289240.

The product of its (nonzero) digits is 21870, while the sum is 37.

The square root of 20530999 is about 4531.1145428029. The cubic root of 20530999 is about 273.8230649475.

The spelling of 20530999 in words is "twenty million, five hundred thirty thousand, nine hundred ninety-nine".