21271402169 has 2 divisors, whose sum is σ = 21271402170. Its totient is φ = 21271402168.

The previous prime is 21271402129. The next prime is 21271402213. The reversal of 21271402169 is 96120417212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12345876544 + 8925525625 = 111112^2 + 94475^2 .

It is a cyclic number.

It is not a de Polignac number, because 21271402169 - 2⁸ = 21271401913 is a prime.

It is a super-2 number, since 2×21271402169² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21271402129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10635701084 + 10635701085.

It is an arithmetic number, because the mean of its divisors is an integer number (10635701085).

Almost surely, 2^21271402169 is an apocalyptic number.

It is an amenable number.

21271402169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21271402169 is an equidigital number, since it uses as much as digits as its factorization.

21271402169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 21271402169 in words is "twenty-one billion, two hundred seventy-one million, four hundred two thousand, one hundred sixty-nine".