21504132016 has 10 divisors (see below), whose sum is σ = 41664255812. Its totient is φ = 10752066000.

The previous prime is 21504132011. The next prime is 21504132017. The reversal of 21504132016 is 61023140512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21504132011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 672004110 + ... + 672004141.

Almost surely, 2^21504132016 is an apocalyptic number.

It is an amenable number.

21504132016 is a deficient number, since it is larger than the sum of its proper divisors (20160123796).

21504132016 is a wasteful number, since it uses less digits than its factorization.

21504132016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1344008259 (or 1344008253 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

Adding to 21504132016 its reverse (61023140512), we get a palindrome (82527272528).

The spelling of 21504132016 in words is "twenty-one billion, five hundred four million, one hundred thirty-two thousand, sixteen".