21245127 has 4 divisors (see below), whose sum is σ = 28326840. Its totient is φ = 14163416.

The previous prime is 21245111. The next prime is 21245129. The reversal of 21245127 is 72154212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21245127 - 2⁴ = 21245111 is a prime.

It is a super-2 number, since 2×21245127² = 902710842492258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21245097 and 21245106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21245129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3540852 + ... + 3540857.

It is an arithmetic number, because the mean of its divisors is an integer number (7081710).

Almost surely, 2^21245127 is an apocalyptic number.

21245127 is a deficient number, since it is larger than the sum of its proper divisors (7081713).

21245127 is an equidigital number, since it uses as much as digits as its factorization.

21245127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7081712.

The product of its digits is 1120, while the sum is 24.

The square root of 21245127 is about 4609.2436472810. The cubic root of 21245127 is about 276.9617388625.

Adding to 21245127 its reverse (72154212), we get a palindrome (93399339).

The spelling of 21245127 in words is "twenty-one million, two hundred forty-five thousand, one hundred twenty-seven".