20913229 has 2 divisors, whose sum is σ = 20913230. Its totient is φ = 20913228.

The previous prime is 20913203. The next prime is 20913271. The reversal of 20913229 is 92231902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20912329 + 900 = 4573^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 20913229 - 2²³ = 12524621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20913197 and 20913206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20913289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10456614 + 10456615.

It is an arithmetic number, because the mean of its divisors is an integer number (10456615).

Almost surely, 2^20913229 is an apocalyptic number.

It is an amenable number.

20913229 is a deficient number, since it is larger than the sum of its proper divisors (1).

20913229 is an equidigital number, since it uses as much as digits as its factorization.

20913229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20913229 is about 4573.0984026150. The cubic root of 20913229 is about 275.5119016206.

The spelling of 20913229 in words is "twenty million, nine hundred thirteen thousand, two hundred twenty-nine".