1200340021 has 4 divisors (see below), whose sum is σ = 1200789100. Its totient is φ = 1199890944.

The previous prime is 1200340007. The next prime is 1200340027. The reversal of 1200340021 is 1200430021.

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 383180625 + 817159396 = 19575^2 + 28586^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200340021 - 2¹⁹ = 1199815733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200339983 and 1200340010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200340027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220506 + ... + 225883.

It is an arithmetic number, because the mean of its divisors is an integer number (300197275).

Almost surely, 2^1200340021 is an apocalyptic number.

It is an amenable number.

1200340021 is a deficient number, since it is larger than the sum of its proper divisors (449079).

1200340021 is an equidigital number, since it uses as much as digits as its factorization.

1200340021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449078.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 1200340021 is about 34645.9235841679. The cubic root of 1200340021 is about 1062.7589281013.

Adding to 1200340021 its reverse (1200430021), we get a palindrome (2400770042).

Subtracting 1200340021 from its reverse (1200430021), we obtain a square (90000 = 300²).

The spelling of 1200340021 in words is "one billion, two hundred million, three hundred forty thousand, twenty-one".