21272269 has 2 divisors, whose sum is σ = 21272270. Its totient is φ = 21272268.

The previous prime is 21272213. The next prime is 21272291. The reversal of 21272269 is 96227212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13235044 + 8037225 = 3638^2 + 2835^2 .

It is a cyclic number.

It is not a de Polignac number, because 21272269 - 2¹⁵ = 21239501 is a prime.

It is a super-2 number, since 2×21272269² = 905018856816722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21272269.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21270269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636134 + 10636135.

It is an arithmetic number, because the mean of its divisors is an integer number (10636135).

Almost surely, 2^21272269 is an apocalyptic number.

It is an amenable number.

21272269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21272269 is an equidigital number, since it uses as much as digits as its factorization.

21272269 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 21272269 is about 4612.1870083508. The cubic root of 21272269 is about 277.0796340785.

The spelling of 21272269 in words is "twenty-one million, two hundred seventy-two thousand, two hundred sixty-nine".