21314921 has 4 divisors (see below), whose sum is σ = 21330000. Its totient is φ = 21299844.

The previous prime is 21314893. The next prime is 21314927. The reversal of 21314921 is 12941312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21314921 - 2⁶ = 21314857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21314927) 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, 5171 + ... + 8328.

It is an arithmetic number, because the mean of its divisors is an integer number (5332500).

Almost surely, 2^21314921 is an apocalyptic number.

It is an amenable number.

21314921 is a deficient number, since it is larger than the sum of its proper divisors (15079).

21314921 is a wasteful number, since it uses less digits than its factorization.

21314921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15078.

The product of its digits is 432, while the sum is 23.

The square root of 21314921 is about 4616.8085297097. The cubic root of 21314921 is about 277.2646967811.

The spelling of 21314921 in words is "twenty-one million, three hundred fourteen thousand, nine hundred twenty-one".