20992291 has 2 divisors, whose sum is σ = 20992292. Its totient is φ = 20992290.

The previous prime is 20992289. The next prime is 20992303. The reversal of 20992291 is 19229902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20992291 - 2¹ = 20992289 is a prime.

Together with 20992289, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20992271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10496145 + 10496146.

It is an arithmetic number, because the mean of its divisors is an integer number (10496146).

Almost surely, 2^20992291 is an apocalyptic number.

20992291 is a deficient number, since it is larger than the sum of its proper divisors (1).

20992291 is an equidigital number, since it uses as much as digits as its factorization.

20992291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 20992291 is about 4581.7344968909. The cubic root of 20992291 is about 275.8586539087.

The spelling of 20992291 in words is "twenty million, nine hundred ninety-two thousand, two hundred ninety-one".