21226251773 has 2 divisors, whose sum is σ = 21226251774. Its totient is φ = 21226251772.

The previous prime is 21226251727. The next prime is 21226251811. The reversal of 21226251773 is 37715262212.

It is an a-pointer prime, because the next prime (21226251811) can be obtained adding 21226251773 to its sum of digits (38).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13351109209 + 7875142564 = 115547^2 + 88742^2 .

It is a cyclic number.

It is not a de Polignac number, because 21226251773 - 2⁸ = 21226251517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21226251703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613125886 + 10613125887.

It is an arithmetic number, because the mean of its divisors is an integer number (10613125887).

Almost surely, 2^21226251773 is an apocalyptic number.

It is an amenable number.

21226251773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226251773 is an equidigital number, since it uses as much as digits as its factorization.

21226251773 is an evil number, because the sum of its binary digits is even.

The product of its digits is 70560, while the sum is 38.

The spelling of 21226251773 in words is "twenty-one billion, two hundred twenty-six million, two hundred fifty-one thousand, seven hundred seventy-three".