21910013 has 2 divisors, whose sum is σ = 21910014. Its totient is φ = 21910012.

The previous prime is 21909989. The next prime is 21910043. The reversal of 21910013 is 31001912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13741849 + 8168164 = 3707^2 + 2858^2 .

It is a cyclic number.

It is not a de Polignac number, because 21910013 - 2¹⁰ = 21908989 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21909973 and 21910000.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21910043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10955006 + 10955007.

It is an arithmetic number, because the mean of its divisors is an integer number (10955007).

Almost surely, 2^21910013 is an apocalyptic number.

It is an amenable number.

21910013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21910013 is an equidigital number, since it uses as much as digits as its factorization.

21910013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 21910013 is about 4680.8132840352. The cubic root of 21910013 is about 279.8213699081.

Adding to 21910013 its reverse (31001912), we get a palindrome (52911925).

The spelling of 21910013 in words is "twenty-one million, nine hundred ten thousand, thirteen".