1200001023021 has 4 divisors (see below), whose sum is σ = 1600001364032. Its totient is φ = 800000682012.

The previous prime is 1200001022977. The next prime is 1200001023047. The reversal of 1200001023021 is 1203201000021.

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 not a de Polignac number, because 1200001023021 - 2²¹ = 1199998925869 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200001022988 and 1200001023006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200001025021) 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, 200000170501 + ... + 200000170506.

It is an arithmetic number, because the mean of its divisors is an integer number (400000341008).

Almost surely, 2^{1200001023021} is an apocalyptic number.

It is an amenable number.

1200001023021 is a deficient number, since it is larger than the sum of its proper divisors (400000341011).

1200001023021 is an equidigital number, since it uses as much as digits as its factorization.

1200001023021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400000341010.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 1200001023021 its reverse (1203201000021), we get a palindrome (2403202023042).

The spelling of 1200001023021 in words is "one trillion, two hundred billion, one million, twenty-three thousand, twenty-one".