21123201427 has 2 divisors, whose sum is σ = 21123201428. Its totient is φ = 21123201426.

The previous prime is 21123201413. The next prime is 21123201433. The reversal of 21123201427 is 72410232112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21123201427 - 2¹⁵ = 21123168659 is a prime.

It is a super-2 number, since 2×21123201427² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21123201487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561600713 + 10561600714.

It is an arithmetic number, because the mean of its divisors is an integer number (10561600714).

Almost surely, 2^21123201427 is an apocalyptic number.

21123201427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123201427 is an equidigital number, since it uses as much as digits as its factorization.

21123201427 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 25.

Adding to 21123201427 its reverse (72410232112), we get a palindrome (93533433539).

The spelling of 21123201427 in words is "twenty-one billion, one hundred twenty-three million, two hundred one thousand, four hundred twenty-seven".