21010524521 has 4 divisors (see below), whose sum is σ = 24012028032. Its totient is φ = 18009021012.

The previous prime is 21010524517. The next prime is 21010524533. The reversal of 21010524521 is 12542501012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21010524521 - 2² = 21010524517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010524511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1500751745 + ... + 1500751758.

It is an arithmetic number, because the mean of its divisors is an integer number (6003007008).

Almost surely, 2^21010524521 is an apocalyptic number.

It is an amenable number.

21010524521 is a deficient number, since it is larger than the sum of its proper divisors (3001503511).

21010524521 is an equidigital number, since it uses as much as digits as its factorization.

21010524521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3001503510.

The product of its (nonzero) digits is 800, while the sum is 23.

The spelling of 21010524521 in words is "twenty-one billion, ten million, five hundred twenty-four thousand, five hundred twenty-one".