12120000021 has 6 divisors (see below), whose sum is σ = 17506666710. Its totient is φ = 8080000008.

The previous prime is 12120000019. The next prime is 12120000023. The reversal of 12120000021 is 12000002121.

It is an interprime number because it is at equal distance from previous prime (12120000019) and next prime (12120000023).

It can be written as a sum of positive squares in only one way, i.e., 6862299921 + 5257700100 = 82839^2 + 72510^2 .

It is not a de Polignac number, because 12120000021 - 2¹ = 12120000019 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 1346666669 = 12120000021 / (1 + 2 + 1 + 2 + 0 + 0 + 0 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 12119999958 and 12120000012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12120000023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 673333326 + ... + 673333343.

It is an arithmetic number, because the mean of its divisors is an integer number (2917777785).

Almost surely, 2^12120000021 is an apocalyptic number.

It is an amenable number.

12120000021 is a deficient number, since it is larger than the sum of its proper divisors (5386666689).

12120000021 is a wasteful number, since it uses less digits than its factorization.

12120000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346666675 (or 1346666672 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 12120000021 its reverse (12000002121), we get a palindrome (24120002142).

The spelling of 12120000021 in words is "twelve billion, one hundred twenty million, twenty-one", and thus it is an aban number.