21226550251421 has 2 divisors, whose sum is σ = 21226550251422. Its totient is φ = 21226550251420.

The previous prime is 21226550251397. The next prime is 21226550251433. The reversal of 21226550251421 is 12415205562212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18703773945796 + 2522776305625 = 4324786^2 + 1588325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21226550251421 is a prime.

It is a super-2 number, since 2×21226550251421² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21226550256421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613275125710 + 10613275125711.

It is an arithmetic number, because the mean of its divisors is an integer number (10613275125711).

Almost surely, 2^{21226550251421} is an apocalyptic number.

It is an amenable number.

21226550251421 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226550251421 is an equidigital number, since it uses as much as digits as its factorization.

21226550251421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96000, while the sum is 38.

The spelling of 21226550251421 in words is "twenty-one trillion, two hundred twenty-six billion, five hundred fifty million, two hundred fifty-one thousand, four hundred twenty-one".