21093601809 has 32 divisors (see below), whose sum is σ = 32465664000. Its totient is φ = 11932844544.

The previous prime is 21093601807. The next prime is 21093601871. The reversal of 21093601809 is 90810639012.

It is not a de Polignac number, because 21093601809 - 2¹ = 21093601807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21093601807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1037857 + ... + 1057985.

It is an arithmetic number, because the mean of its divisors is an integer number (1014552000).

Almost surely, 2^21093601809 is an apocalyptic number.

It is an amenable number.

21093601809 is a deficient number, since it is larger than the sum of its proper divisors (11372062191).

21093601809 is a wasteful number, since it uses less digits than its factorization.

21093601809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20637.

The product of its (nonzero) digits is 23328, while the sum is 39.

The spelling of 21093601809 in words is "twenty-one billion, ninety-three million, six hundred one thousand, eight hundred nine".