21314251 has 4 divisors (see below), whose sum is σ = 24359152. Its totient is φ = 18269352.

The previous prime is 21314233. The next prime is 21314269. The reversal of 21314251 is 15241312.

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

It is an interprime number because it is at equal distance from previous prime (21314233) and next prime (21314269).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21314251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21314221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1522440 + ... + 1522453.

It is an arithmetic number, because the mean of its divisors is an integer number (6089788).

Almost surely, 2^21314251 is an apocalyptic number.

21314251 is a deficient number, since it is larger than the sum of its proper divisors (3044901).

21314251 is an equidigital number, since it uses as much as digits as its factorization.

21314251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3044900.

The product of its digits is 240, while the sum is 19.

The square root of 21314251 is about 4616.7359681922. The cubic root of 21314251 is about 277.2617916285.

Adding to 21314251 its reverse (15241312), we get a palindrome (36555563).

The spelling of 21314251 in words is "twenty-one million, three hundred fourteen thousand, two hundred fifty-one".