21813683 has 8 divisors (see below), whose sum is σ = 23378208. Its totient is φ = 20300544.

The previous prime is 21813679. The next prime is 21813689. The reversal of 21813683 is 38631812.

It is a happy number.

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 21813683 - 2² = 21813679 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21813689) 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, 11966 + ... + 13667.

It is an arithmetic number, because the mean of its divisors is an integer number (2922276).

Almost surely, 2^21813683 is an apocalyptic number.

21813683 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21813683 is a deficient number, since it is larger than the sum of its proper divisors (1564525).

21813683 is a wasteful number, since it uses less digits than its factorization.

21813683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25693.

The product of its digits is 6912, while the sum is 32.

The square root of 21813683 is about 4670.5120704265. The cubic root of 21813683 is about 279.4106780287.

The spelling of 21813683 in words is "twenty-one million, eight hundred thirteen thousand, six hundred eighty-three".