21242515321 has 8 divisors (see below), whose sum is σ = 21514118400. Its totient is φ = 20970980160.

The previous prime is 21242515309. The next prime is 21242515331. The reversal of 21242515321 is 12351524212.

It is a happy number.

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 21242515321 - 2⁷ = 21242515193 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 21242515321.

It is not an unprimeable number, because it can be changed into a prime (21242515331) 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, 991836 + ... + 1013026.

It is an arithmetic number, because the mean of its divisors is an integer number (2689264800).

Almost surely, 2^21242515321 is an apocalyptic number.

It is an amenable number.

21242515321 is a deficient number, since it is larger than the sum of its proper divisors (271603079).

21242515321 is a wasteful number, since it uses less digits than its factorization.

21242515321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33959.

The product of its digits is 4800, while the sum is 28.

The spelling of 21242515321 in words is "twenty-one billion, two hundred forty-two million, five hundred fifteen thousand, three hundred twenty-one".