21827471 has 2 divisors, whose sum is σ = 21827472. Its totient is φ = 21827470.

The previous prime is 21827453. The next prime is 21827479. The reversal of 21827471 is 17472812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21827471 - 2¹⁴ = 21811087 is a prime.

It is a super-3 number, since 3×21827471³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21827479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10913735 + 10913736.

It is an arithmetic number, because the mean of its divisors is an integer number (10913736).

Almost surely, 2^21827471 is an apocalyptic number.

21827471 is a deficient number, since it is larger than the sum of its proper divisors (1).

21827471 is an equidigital number, since it uses as much as digits as its factorization.

21827471 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6272, while the sum is 32.

The square root of 21827471 is about 4671.9879066624. The cubic root of 21827471 is about 279.4695356276.

The spelling of 21827471 in words is "twenty-one million, eight hundred twenty-seven thousand, four hundred seventy-one".