21103933 has 2 divisors, whose sum is σ = 21103934. Its totient is φ = 21103932.

The previous prime is 21103897. The next prime is 21103937. The reversal of 21103933 is 33930112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18679684 + 2424249 = 4322^2 + 1557^2 .

It is a cyclic number.

It is not a de Polignac number, because 21103933 - 2²¹ = 19006781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21103937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551966 + 10551967.

It is an arithmetic number, because the mean of its divisors is an integer number (10551967).

Almost surely, 2^21103933 is an apocalyptic number.

It is an amenable number.

21103933 is a deficient number, since it is larger than the sum of its proper divisors (1).

21103933 is an equidigital number, since it uses as much as digits as its factorization.

21103933 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 22.

The square root of 21103933 is about 4593.9017185830. The cubic root of 21103933 is about 276.3468168664.

The spelling of 21103933 in words is "twenty-one million, one hundred three thousand, nine hundred thirty-three".