1200000000021 has 32 divisors (see below), whose sum is σ = 1670859134208. Its totient is φ = 765356014080.

The previous prime is 1199999999993. The next prime is 1200000000053.

It is a happy number.

1200000000021 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1200000000021 - 2¹⁸ = 1199999737877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1199999999928 and 1200000000009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200000001021) 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, 2735505 + ... + 3143721.

It is an arithmetic number, because the mean of its divisors is an integer number (52214347944).

Almost surely, 2^{1200000000021} is an apocalyptic number.

It is an amenable number.

1200000000021 is a deficient number, since it is larger than the sum of its proper divisors (470859134187).

1200000000021 is a wasteful number, since it uses less digits than its factorization.

1200000000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408701.

The product of its (nonzero) digits is 4, while the sum is 6.

It can be divided in two parts, 12000000000 and 21, that added together give a palindrome (12000000021).

The spelling of 1200000000021 in words is "one trillion, two hundred billion, twenty-one", and thus it is an aban number.