21827123 has 2 divisors, whose sum is σ = 21827124. Its totient is φ = 21827122.

The previous prime is 21827119. The next prime is 21827137. The reversal of 21827123 is 32172812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21827123 - 2² = 21827119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21827092 and 21827101.

It is not a weakly prime, because it can be changed into another prime (21827173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10913561 + 10913562.

It is an arithmetic number, because the mean of its divisors is an integer number (10913562).

Almost surely, 2^21827123 is an apocalyptic number.

21827123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21827123 is an equidigital number, since it uses as much as digits as its factorization.

21827123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 21827123 is about 4671.9506632669. The cubic root of 21827123 is about 279.4680504057.

Adding to 21827123 its reverse (32172812), we get a palindrome (53999935).

The spelling of 21827123 in words is "twenty-one million, eight hundred twenty-seven thousand, one hundred twenty-three".