21003053 has 2 divisors, whose sum is σ = 21003054. Its totient is φ = 21003052.

The previous prime is 21003011. The next prime is 21003079. The reversal of 21003053 is 35030012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13675204 + 7327849 = 3698^2 + 2707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003053 - 2⁸ = 21002797 is a prime.

It is a super-2 number, since 2×21003053² = 882256470641618, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21003083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501526 + 10501527.

It is an arithmetic number, because the mean of its divisors is an integer number (10501527).

Almost surely, 2^21003053 is an apocalyptic number.

It is an amenable number.

21003053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003053 is an equidigital number, since it uses as much as digits as its factorization.

21003053 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90, while the sum is 14.

The square root of 21003053 is about 4582.9087924592. The cubic root of 21003053 is about 275.9057868244.

Adding to 21003053 its reverse (35030012), we get a palindrome (56033065).

The spelling of 21003053 in words is "twenty-one million, three thousand, fifty-three".