21683081 has 8 divisors (see below), whose sum is σ = 24809664. Its totient is φ = 18563760.

The previous prime is 21683071. The next prime is 21683087. The reversal of 21683081 is 18038612.

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 21683081 - 2⁶ = 21683017 is a prime.

It is a super-2 number, since 2×21683081² = 940312003305122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21683087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8546 + ... + 10788.

It is an arithmetic number, because the mean of its divisors is an integer number (3101208).

Almost surely, 2^21683081 is an apocalyptic number.

It is an amenable number.

21683081 is a deficient number, since it is larger than the sum of its proper divisors (3126583).

21683081 is a wasteful number, since it uses less digits than its factorization.

21683081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3631.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 21683081 is about 4656.5095296799. The cubic root of 21683081 is about 278.8519360138.

The spelling of 21683081 in words is "twenty-one million, six hundred eighty-three thousand, eighty-one".