21243524451 has 8 divisors (see below), whose sum is σ = 28329959424. Its totient is φ = 14159719560.

The previous prime is 21243524437. The next prime is 21243524453. The reversal of 21243524451 is 15442534212.

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

It is not a de Polignac number, because 21243524451 - 2¹¹ = 21243522403 is a prime.

It is a super-2 number, since 2×21243524451² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21243524453) 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 7 ways as a sum of consecutive naturals, for example, 638595 + ... + 671036.

It is an arithmetic number, because the mean of its divisors is an integer number (3541244928).

Almost surely, 2^21243524451 is an apocalyptic number.

21243524451 is a deficient number, since it is larger than the sum of its proper divisors (7086434973).

21243524451 is a wasteful number, since it uses less digits than its factorization.

21243524451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1315041.

The product of its digits is 38400, while the sum is 33.

The spelling of 21243524451 in words is "twenty-one billion, two hundred forty-three million, five hundred twenty-four thousand, four hundred fifty-one".