21580229521 has 16 divisors (see below), whose sum is σ = 22099392000. Its totient is φ = 21068264448.

The previous prime is 21580229497. The next prime is 21580229543. The reversal of 21580229521 is 12592208512.

It is a cyclic number.

It is not a de Polignac number, because 21580229521 - 2³¹ = 19432745873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21580229581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3994380 + ... + 3999778.

It is an arithmetic number, because the mean of its divisors is an integer number (1381212000).

Almost surely, 2^21580229521 is an apocalyptic number.

It is an amenable number.

21580229521 is a deficient number, since it is larger than the sum of its proper divisors (519162479).

21580229521 is an equidigital number, since it uses as much as digits as its factorization.

21580229521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6048.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 21580229521 in words is "twenty-one billion, five hundred eighty million, two hundred twenty-nine thousand, five hundred twenty-one".