21683963 has 8 divisors (see below), whose sum is σ = 25859328. Its totient is φ = 17778024.

The previous prime is 21683951. The next prime is 21683969. The reversal of 21683963 is 36938612.

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 21683963 - 2⁶ = 21683899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21683969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67181 + ... + 67502.

It is an arithmetic number, because the mean of its divisors is an integer number (3232416).

Almost surely, 2^21683963 is an apocalyptic number.

21683963 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21683963 is a deficient number, since it is larger than the sum of its proper divisors (4175365).

21683963 is a wasteful number, since it uses less digits than its factorization.

21683963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134713.

The product of its digits is 46656, while the sum is 38.

The square root of 21683963 is about 4656.6042348475. The cubic root of 21683963 is about 278.8557169044.

The spelling of 21683963 in words is "twenty-one million, six hundred eighty-three thousand, nine hundred sixty-three".