21234973 has 2 divisors, whose sum is σ = 21234974. Its totient is φ = 21234972.

The previous prime is 21234953. The next prime is 21235001. The reversal of 21234973 is 37943212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20412324 + 822649 = 4518^2 + 907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234973 - 2⁹ = 21234461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21234923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617486 + 10617487.

It is an arithmetic number, because the mean of its divisors is an integer number (10617487).

Almost surely, 2^21234973 is an apocalyptic number.

It is an amenable number.

21234973 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234973 is an equidigital number, since it uses as much as digits as its factorization.

21234973 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 31.

The square root of 21234973 is about 4608.1420334013. The cubic root of 21234973 is about 276.9176076812.

The spelling of 21234973 in words is "twenty-one million, two hundred thirty-four thousand, nine hundred seventy-three".