11909301821 has 4 divisors (see below), whose sum is σ = 12536107200. Its totient is φ = 11282496444.

The previous prime is 11909301799. The next prime is 11909301829. The reversal of 11909301821 is 12810390911.

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 a de Polignac number, because none of the positive numbers 2^k-11909301821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11909301829) 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, 313402661 + ... + 313402698.

It is an arithmetic number, because the mean of its divisors is an integer number (3134026800).

Almost surely, 2^11909301821 is an apocalyptic number.

It is an amenable number.

11909301821 is a deficient number, since it is larger than the sum of its proper divisors (626805379).

11909301821 is an equidigital number, since it uses as much as digits as its factorization.

11909301821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626805378.

The product of its (nonzero) digits is 3888, while the sum is 35.

The spelling of 11909301821 in words is "eleven billion, nine hundred nine million, three hundred one thousand, eight hundred twenty-one".