1211021000009 has 4 divisors (see below), whose sum is σ = 1216760436240. Its totient is φ = 1205281563780.

The previous prime is 1211020999961. The next prime is 1211021000029. The reversal of 1211021000009 is 9000001201121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1211021000009 - 2³² = 1206726032713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211021000029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2869717799 + ... + 2869718220.

It is an arithmetic number, because the mean of its divisors is an integer number (304190109060).

Almost surely, 2^{1211021000009} is an apocalyptic number.

It is an amenable number.

1211021000009 is a deficient number, since it is larger than the sum of its proper divisors (5739436231).

1211021000009 is an equidigital number, since it uses as much as digits as its factorization.

1211021000009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5739436230.

The product of its (nonzero) digits is 36, while the sum is 17.

The spelling of 1211021000009 in words is "one trillion, two hundred eleven billion, twenty-one million, nine", and thus it is an aban number.