20999159 has 2 divisors, whose sum is σ = 20999160. Its totient is φ = 20999158.

The previous prime is 20999149. The next prime is 20999171. The reversal of 20999159 is 95199902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20999159 - 2¹² = 20995063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20999149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10499579 + 10499580.

It is an arithmetic number, because the mean of its divisors is an integer number (10499580).

Almost surely, 2^20999159 is an apocalyptic number.

20999159 is a deficient number, since it is larger than the sum of its proper divisors (1).

20999159 is an equidigital number, since it uses as much as digits as its factorization.

20999159 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 65610, while the sum is 44.

The square root of 20999159 is about 4582.4839334143. The cubic root of 20999159 is about 275.8887346441. Note that the first 3 decimals are identical.

The spelling of 20999159 in words is "twenty million, nine hundred ninety-nine thousand, one hundred fifty-nine".