21250246122221 has 2 divisors, whose sum is σ = 21250246122222. Its totient is φ = 21250246122220.

The previous prime is 21250246122191. The next prime is 21250246122247. The reversal of 21250246122221 is 12222164205212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11881223017225 + 9369023104996 = 3446915^2 + 3060886^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250246122221 - 2²² = 21250241927917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250246622221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625123061110 + 10625123061111.

It is an arithmetic number, because the mean of its divisors is an integer number (10625123061111).

Almost surely, 2^{21250246122221} is an apocalyptic number.

It is an amenable number.

21250246122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250246122221 is an equidigital number, since it uses as much as digits as its factorization.

21250246122221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15360, while the sum is 32.

The spelling of 21250246122221 in words is "twenty-one trillion, two hundred fifty billion, two hundred forty-six million, one hundred twenty-two thousand, two hundred twenty-one".