21103983 has 10 divisors (see below), whose sum is σ = 31525824. Its totient is φ = 14069268.

The previous prime is 21103961. The next prime is 21104011. The reversal of 21103983 is 38930112.

It is not a de Polignac number, because 21103983 - 2¹² = 21099887 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 130191 + ... + 130352.

Almost surely, 2^21103983 is an apocalyptic number.

21103983 is a deficient number, since it is larger than the sum of its proper divisors (10421841).

21103983 is an equidigital number, since it uses as much as digits as its factorization.

21103983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260555 (or 260546 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21103983 is about 4593.9071605769. The cubic root of 21103983 is about 276.3470351089.

The spelling of 21103983 in words is "twenty-one million, one hundred three thousand, nine hundred eighty-three".