21225238679 has 2 divisors, whose sum is σ = 21225238680. Its totient is φ = 21225238678.

The previous prime is 21225238651. The next prime is 21225238717. The reversal of 21225238679 is 97683252212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21225238679 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21225238609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612619339 + 10612619340.

It is an arithmetic number, because the mean of its divisors is an integer number (10612619340).

Almost surely, 2^21225238679 is an apocalyptic number.

21225238679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225238679 is an equidigital number, since it uses as much as digits as its factorization.

21225238679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 725760, while the sum is 47.

The spelling of 21225238679 in words is "twenty-one billion, two hundred twenty-five million, two hundred thirty-eight thousand, six hundred seventy-nine".