21683361 has 8 divisors (see below), whose sum is σ = 33041344. Its totient is φ = 12390480.

The previous prime is 21683359. The next prime is 21683371. The reversal of 21683361 is 16338612.

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

It is not a de Polignac number, because 21683361 - 2¹ = 21683359 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21683371) 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, 516250 + ... + 516291.

It is an arithmetic number, because the mean of its divisors is an integer number (4130168).

Almost surely, 2^21683361 is an apocalyptic number.

21683361 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21683361 is a deficient number, since it is larger than the sum of its proper divisors (11357983).

21683361 is a wasteful number, since it uses less digits than its factorization.

21683361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032551.

The product of its digits is 5184, while the sum is 30.

The square root of 21683361 is about 4656.5395950212. The cubic root of 21683361 is about 278.8531363076.

The spelling of 21683361 in words is "twenty-one million, six hundred eighty-three thousand, three hundred sixty-one".