21222202021157 has 2 divisors, whose sum is σ = 21222202021158. Its totient is φ = 21222202021156.

The previous prime is 21222202021151. The next prime is 21222202021201. The reversal of 21222202021157 is 75112020222212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15676737496996 + 5545464524161 = 3959386^2 + 2354881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21222202021157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222202021151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611101010578 + 10611101010579.

It is an arithmetic number, because the mean of its divisors is an integer number (10611101010579).

Almost surely, 2^{21222202021157} is an apocalyptic number.

It is an amenable number.

21222202021157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222202021157 is an equidigital number, since it uses as much as digits as its factorization.

21222202021157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 29.

Adding to 21222202021157 its reverse (75112020222212), we get a palindrome (96334222243369).

The spelling of 21222202021157 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred two million, twenty-one thousand, one hundred fifty-seven".