21000383 has 4 divisors (see below), whose sum is σ = 21488808. Its totient is φ = 20511960.

The previous prime is 21000367. The next prime is 21000391. The reversal of 21000383 is 38300012.

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 21000383 - 2⁴ = 21000367 is a prime.

It is a super-2 number, since 2×21000383² = 882032172293378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244148 + ... + 244233.

It is an arithmetic number, because the mean of its divisors is an integer number (5372202).

Almost surely, 2^21000383 is an apocalyptic number.

21000383 is a deficient number, since it is larger than the sum of its proper divisors (488425).

21000383 is an equidigital number, since it uses as much as digits as its factorization.

21000383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488424.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21000383 is about 4582.6174834913. The cubic root of 21000383 is about 275.8940948786.

Adding to 21000383 its reverse (38300012), we get a palindrome (59300395).

The spelling of 21000383 in words is "twenty-one million, three hundred eighty-three", and thus it is an aban number.