21012053 has 2 divisors, whose sum is σ = 21012054. Its totient is φ = 21012052.

The previous prime is 21011981. The next prime is 21012059. The reversal of 21012053 is 35021012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20593444 + 418609 = 4538^2 + 647^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012053 - 2¹⁶ = 20946517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506026 + 10506027.

It is an arithmetic number, because the mean of its divisors is an integer number (10506027).

Almost surely, 2^21012053 is an apocalyptic number.

It is an amenable number.

21012053 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012053 is an equidigital number, since it uses as much as digits as its factorization.

21012053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 21012053 is about 4583.8905964257. The cubic root of 21012053 is about 275.9451905797.

Adding to 21012053 its reverse (35021012), we get a palindrome (56033065).

The spelling of 21012053 in words is "twenty-one million, twelve thousand, fifty-three".