21221122873 has 2 divisors, whose sum is σ = 21221122874. Its totient is φ = 21221122872.

The previous prime is 21221122847. The next prime is 21221122877. The reversal of 21221122873 is 37822112212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16299118224 + 4922004649 = 127668^2 + 70157^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221122873 - 2⁹ = 21221122361 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221122877) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610561436 + 10610561437.

It is an arithmetic number, because the mean of its divisors is an integer number (10610561437).

Almost surely, 2^21221122873 is an apocalyptic number.

It is an amenable number.

21221122873 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221122873 is an equidigital number, since it uses as much as digits as its factorization.

21221122873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 31.

The spelling of 21221122873 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, eight hundred seventy-three".