21290683 has 4 divisors (see below), whose sum is σ = 21692448. Its totient is φ = 20888920.

The previous prime is 21290653. The next prime is 21290693. The reversal of 21290683 is 38609212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21290683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21290623) 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, 200803 + ... + 200908.

It is an arithmetic number, because the mean of its divisors is an integer number (5423112).

Almost surely, 2^21290683 is an apocalyptic number.

21290683 is a deficient number, since it is larger than the sum of its proper divisors (401765).

21290683 is an equidigital number, since it uses as much as digits as its factorization.

21290683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401764.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 21290683 is about 4614.1828095558. The cubic root of 21290683 is about 277.1595608742.

Adding to 21290683 its reverse (38609212), we get a palindrome (59899895).

The spelling of 21290683 in words is "twenty-one million, two hundred ninety thousand, six hundred eighty-three".