21520525243 has 8 divisors (see below), whose sum is σ = 24658115040. Its totient is φ = 18398742720.

The previous prime is 21520525241. The next prime is 21520525259. The reversal of 21520525243 is 34252502512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21520525243 - 2¹ = 21520525241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21520525241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3948898 + ... + 3954343.

It is an arithmetic number, because the mean of its divisors is an integer number (3082264380).

Almost surely, 2^21520525243 is an apocalyptic number.

21520525243 is a deficient number, since it is larger than the sum of its proper divisors (3137589797).

21520525243 is an equidigital number, since it uses as much as digits as its factorization.

21520525243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7903637.

The product of its (nonzero) digits is 24000, while the sum is 31.

The spelling of 21520525243 in words is "twenty-one billion, five hundred twenty million, five hundred twenty-five thousand, two hundred forty-three".