21383207 has 8 divisors (see below), whose sum is σ = 21750960. Its totient is φ = 21018240.

The previous prime is 21383183. The next prime is 21383209. The reversal of 21383207 is 70238312.

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

It is a cyclic number.

It is not a de Polignac number, because 21383207 - 2⁶ = 21383143 is a prime.

It is a Duffinian number.

21383207 is a modest number, since divided by 3207 gives 2138 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383209) 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, 19469 + ... + 20537.

It is an arithmetic number, because the mean of its divisors is an integer number (2718870).

Almost surely, 2^21383207 is an apocalyptic number.

21383207 is a deficient number, since it is larger than the sum of its proper divisors (367753).

21383207 is a wasteful number, since it uses less digits than its factorization.

21383207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1393.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21383207 is about 4624.1979845158. The cubic root of 21383207 is about 277.5604694671.

The spelling of 21383207 in words is "twenty-one million, three hundred eighty-three thousand, two hundred seven".