21012000212521 has 2 divisors, whose sum is σ = 21012000212522. Its totient is φ = 21012000212520.

The previous prime is 21012000212389. The next prime is 21012000212527. The reversal of 21012000212521 is 12521200021012.

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., 20151300560400 + 860699652121 = 4489020^2 + 927739^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012000212521 - 2²⁷ = 21011865994793 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012000212527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506000106260 + 10506000106261.

It is an arithmetic number, because the mean of its divisors is an integer number (10506000106261).

Almost surely, 2^{21012000212521} is an apocalyptic number.

It is an amenable number.

21012000212521 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012000212521 is an equidigital number, since it uses as much as digits as its factorization.

21012000212521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 19.

Adding to 21012000212521 its reverse (12521200021012), we get a palindrome (33533200233533).

The spelling of 21012000212521 in words is "twenty-one trillion, twelve billion, two hundred twelve thousand, five hundred twenty-one".