21513203 has 2 divisors, whose sum is σ = 21513204. Its totient is φ = 21513202.

The previous prime is 21513197. The next prime is 21513209. The reversal of 21513203 is 30231512.

It is a balanced prime because it is at equal distance from previous prime (21513197) and next prime (21513209).

It is a cyclic number.

It is not a de Polignac number, because 21513203 - 2¹⁴ = 21496819 is a prime.

It is not a weakly prime, because it can be changed into another prime (21513209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10756601 + 10756602.

It is an arithmetic number, because the mean of its divisors is an integer number (10756602).

Almost surely, 2^21513203 is an apocalyptic number.

21513203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21513203 is an equidigital number, since it uses as much as digits as its factorization.

21513203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21513203 is about 4638.2327453460. The cubic root of 21513203 is about 278.1217959148.

Adding to 21513203 its reverse (30231512), we get a palindrome (51744715).

The spelling of 21513203 in words is "twenty-one million, five hundred thirteen thousand, two hundred three".