21812127 has 8 divisors (see below), whose sum is σ = 30021120. Its totient is φ = 14072280.

The previous prime is 21812113. The next prime is 21812143. The reversal of 21812127 is 72121812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21812127 - 2⁴ = 21812111 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21812097 and 21812106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21812107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117177 + ... + 117362.

It is an arithmetic number, because the mean of its divisors is an integer number (3752640).

Almost surely, 2^21812127 is an apocalyptic number.

21812127 is a deficient number, since it is larger than the sum of its proper divisors (8208993).

21812127 is a wasteful number, since it uses less digits than its factorization.

21812127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234573.

The product of its digits is 448, while the sum is 24.

The square root of 21812127 is about 4670.3454904322. The cubic root of 21812127 is about 279.4040342881.

Adding to 21812127 its reverse (72121812), we get a palindrome (93933939).

The spelling of 21812127 in words is "twenty-one million, eight hundred twelve thousand, one hundred twenty-seven".