11920000021 has 4 divisors (see below), whose sum is σ = 11969460844. Its totient is φ = 11870539200.

The previous prime is 11920000009. The next prime is 11920000051. The reversal of 11920000021 is 12000002911.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6266463921 + 5653536100 = 79161^2 + 75190^2 .

It is a cyclic number.

It is not a de Polignac number, because 11920000021 - 2⁵ = 11919999989 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 (11920000051) 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, 24730050 + ... + 24730531.

It is an arithmetic number, because the mean of its divisors is an integer number (2992365211).

Almost surely, 2^11920000021 is an apocalyptic number.

It is an amenable number.

11920000021 is a deficient number, since it is larger than the sum of its proper divisors (49460823).

11920000021 is an equidigital number, since it uses as much as digits as its factorization.

11920000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49460822.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 11920000021 its reverse (12000002911), we get a palindrome (23920002932).

The spelling of 11920000021 in words is "eleven billion, nine hundred twenty million, twenty-one", and thus it is an aban number.