1201000021 has 12 divisors (see below), whose sum is σ = 1302725028. Its totient is φ = 1106711424.

The previous prime is 1201000007. The next prime is 1201000027. The reversal of 1201000021 is 1200001021.

It can be written as a sum of positive squares in 6 ways, for example, as 249956100 + 951043921 = 15810^2 + 30839^2 .

It is not a de Polignac number, because 1201000021 - 2⁹ = 1200999509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200999968 and 1201000013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201000027) 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 11 ways as a sum of consecutive naturals, for example, 97801 + ... + 109393.

It is an arithmetic number, because the mean of its divisors is an integer number (108560419).

Almost surely, 2^1201000021 is an apocalyptic number.

It is an amenable number.

1201000021 is a deficient number, since it is larger than the sum of its proper divisors (101725007).

1201000021 is a wasteful number, since it uses less digits than its factorization.

1201000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12232 (or 12219 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 1201000021 is about 34655.4472053096. The cubic root of 1201000021 is about 1062.9536763566.

Adding to 1201000021 its reverse (1200001021), we get a palindrome (2401001042).

The spelling of 1201000021 in words is "one billion, two hundred one million, twenty-one", and thus it is an aban number.