21136403 has 2 divisors, whose sum is σ = 21136404. Its totient is φ = 21136402.

The previous prime is 21136393. The next prime is 21136429. The reversal of 21136403 is 30463112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21136403 - 2⁸ = 21136147 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21136433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10568201 + 10568202.

It is an arithmetic number, because the mean of its divisors is an integer number (10568202).

Almost surely, 2^21136403 is an apocalyptic number.

21136403 is a deficient number, since it is larger than the sum of its proper divisors (1).

21136403 is an equidigital number, since it uses as much as digits as its factorization.

21136403 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 21136403 is about 4597.4343932241. The cubic root of 21136403 is about 276.4884710816.

Adding to 21136403 its reverse (30463112), we get a palindrome (51599515).

The spelling of 21136403 in words is "twenty-one million, one hundred thirty-six thousand, four hundred three".