21012535241 has 4 divisors (see below), whose sum is σ = 21013977732. Its totient is φ = 21011092752.

The previous prime is 21012535231. The next prime is 21012535253. The reversal of 21012535241 is 14253521012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7187478841 + 13825056400 = 84779^2 + 117580^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012535241 - 2¹⁸ = 21012273097 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21012535241.

It is not an unprimeable number, because it can be changed into a prime (21012535231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 699170 + ... + 728603.

It is an arithmetic number, because the mean of its divisors is an integer number (5253494433).

Almost surely, 2^21012535241 is an apocalyptic number.

It is an amenable number.

21012535241 is a deficient number, since it is larger than the sum of its proper divisors (1442491).

21012535241 is a wasteful number, since it uses less digits than its factorization.

21012535241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442490.

The product of its (nonzero) digits is 2400, while the sum is 26.

The spelling of 21012535241 in words is "twenty-one billion, twelve million, five hundred thirty-five thousand, two hundred forty-one".