21000683 has 4 divisors (see below), whose sum is σ = 22909848. Its totient is φ = 19091520.

The previous prime is 21000677. The next prime is 21000689. The reversal of 21000683 is 38600012.

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 (21000677) and next prime (21000689).

It is a cyclic number.

It is not a de Polignac number, because 21000683 - 2¹⁰ = 20999659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000689) 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, 954566 + ... + 954587.

It is an arithmetic number, because the mean of its divisors is an integer number (5727462).

Almost surely, 2^21000683 is an apocalyptic number.

21000683 is a deficient number, since it is larger than the sum of its proper divisors (1909165).

21000683 is a wasteful number, since it uses less digits than its factorization.

21000683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1909164.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 21000683 is about 4582.6502157594. The cubic root of 21000683 is about 275.8954086298.

Adding to 21000683 its reverse (38600012), we get a palindrome (59600695).

The spelling of 21000683 in words is "twenty-one million, six hundred eighty-three", and thus it is an aban number.