20099231 has 2 divisors, whose sum is σ = 20099232. Its totient is φ = 20099230.

The previous prime is 20099173. The next prime is 20099267. The reversal of 20099231 is 13299002.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20099231 - 2¹⁸ = 19837087 is a prime.

It is a super-2 number, since 2×20099231² = 807958173582722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20099231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20093231) 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 as a sum of consecutive naturals, namely, 10049615 + 10049616.

It is an arithmetic number, because the mean of its divisors is an integer number (10049616).

Almost surely, 2^20099231 is an apocalyptic number.

20099231 is a deficient number, since it is larger than the sum of its proper divisors (1).

20099231 is an equidigital number, since it uses as much as digits as its factorization.

20099231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 20099231 is about 4483.2165907973. The cubic root of 20099231 is about 271.8899452039.

The spelling of 20099231 in words is "twenty million, ninety-nine thousand, two hundred thirty-one".