21355087009 has 8 divisors (see below), whose sum is σ = 21410978400. Its totient is φ = 21299233536.

The previous prime is 21355086997. The next prime is 21355087027. The reversal of 21355087009 is 90078055312.

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 21355087009 - 2¹⁹ = 21354562721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21355087049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1376554 + ... + 1391980.

It is an arithmetic number, because the mean of its divisors is an integer number (2676372300).

Almost surely, 2^21355087009 is an apocalyptic number.

It is an amenable number.

21355087009 is a deficient number, since it is larger than the sum of its proper divisors (55891391).

21355087009 is a wasteful number, since it uses less digits than its factorization.

21355087009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18959.

The product of its (nonzero) digits is 75600, while the sum is 40.

The spelling of 21355087009 in words is "twenty-one billion, three hundred fifty-five million, eighty-seven thousand, nine".