21030983 has 6 divisors (see below), whose sum is σ = 21438144. Its totient is φ = 20631416.

The previous prime is 21030979. The next prime is 21031009. The reversal of 21030983 is 38903012.

It is not a de Polignac number, because 21030983 - 2² = 21030979 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 935 + ... + 6552.

It is an arithmetic number, because the mean of its divisors is an integer number (3573024).

Almost surely, 2^21030983 is an apocalyptic number.

21030983 is a deficient number, since it is larger than the sum of its proper divisors (407161).

21030983 is an frugal number, since it uses more digits than its factorization.

21030983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7593 (or 7540 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21030983 is about 4585.9549714318. The cubic root of 21030983 is about 276.0280331044.

Adding to 21030983 its reverse (38903012), we get a palindrome (59933995).

The spelling of 21030983 in words is "twenty-one million, thirty thousand, nine hundred eighty-three".