21240983 has 10 divisors (see below), whose sum is σ = 22903320. Its totient is φ = 19662060.

The previous prime is 21240977. The next prime is 21240991. The reversal of 21240983 is 38904212.

It is not a de Polignac number, because 21240983 - 2¹⁶ = 21175447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240913) 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, 685178 + ... + 685208.

It is an arithmetic number, because the mean of its divisors is an integer number (2290332).

Almost surely, 2^21240983 is an apocalyptic number.

21240983 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21240983 is a deficient number, since it is larger than the sum of its proper divisors (1662337).

21240983 is an frugal number, since it uses more digits than its factorization.

21240983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21240983 is about 4608.7940939035. The cubic root of 21240983 is about 276.9437299629.

The spelling of 21240983 in words is "twenty-one million, two hundred forty thousand, nine hundred eighty-three".