21801306009 has 32 divisors (see below), whose sum is σ = 33764469760. Its totient is φ = 12254628672.

The previous prime is 21801306001. The next prime is 21801306049. The reversal of 21801306009 is 90060310812.

It is not a de Polignac number, because 21801306009 - 2³ = 21801306001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21801306001) 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, 1020762 + ... + 1041900.

It is an arithmetic number, because the mean of its divisors is an integer number (1055139680).

Almost surely, 2^21801306009 is an apocalyptic number.

It is an amenable number.

21801306009 is a deficient number, since it is larger than the sum of its proper divisors (11963163751).

21801306009 is a wasteful number, since it uses less digits than its factorization.

21801306009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21949.

The product of its (nonzero) digits is 2592, while the sum is 30.

The spelling of 21801306009 in words is "twenty-one billion, eight hundred one million, three hundred six thousand, nine".