21083963 has 4 divisors (see below), whose sum is σ = 21598248. Its totient is φ = 20569680.

The previous prime is 21083941. The next prime is 21083989. The reversal of 21083963 is 36938012.

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

It is a cyclic number.

It is not a de Polignac number, because 21083963 - 2¹⁰ = 21082939 is a prime.

It is a super-3 number, since 3×21083963³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21083903) 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, 257081 + ... + 257162.

It is an arithmetic number, because the mean of its divisors is an integer number (5399562).

Almost surely, 2^21083963 is an apocalyptic number.

21083963 is a deficient number, since it is larger than the sum of its proper divisors (514285).

21083963 is an equidigital number, since it uses as much as digits as its factorization.

21083963 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514284.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21083963 is about 4591.7276704961. The cubic root of 21083963 is about 276.2596232051.

The spelling of 21083963 in words is "twenty-one million, eighty-three thousand, nine hundred sixty-three".