21324421515 has 32 divisors (see below), whose sum is σ = 35715796992. Its totient is φ = 10851120000.

The previous prime is 21324421493. The next prime is 21324421553. The reversal of 21324421515 is 51512442312.

It is not a de Polignac number, because 21324421515 - 2⁶ = 21324421451 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 289936 + ... + 355965.

It is an arithmetic number, because the mean of its divisors is an integer number (1116118656).

Almost surely, 2^21324421515 is an apocalyptic number.

21324421515 is a deficient number, since it is larger than the sum of its proper divisors (14391375477).

21324421515 is a wasteful number, since it uses less digits than its factorization.

21324421515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646011.

The product of its digits is 9600, while the sum is 30.

Adding to 21324421515 its reverse (51512442312), we get a palindrome (72836863827).

The spelling of 21324421515 in words is "twenty-one billion, three hundred twenty-four million, four hundred twenty-one thousand, five hundred fifteen".