1201200021 has 24 divisors (see below), whose sum is σ = 1986551424. Its totient is φ = 685147680.

The previous prime is 1201199963. The next prime is 1201200029. The reversal of 1201200021 is 1200021021.

It is not a de Polignac number, because 1201200021 - 2¹³ = 1201191829 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 1201199976 and 1201200012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201200029) 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 23 ways as a sum of consecutive naturals, for example, 17976 + ... + 52206.

It is an arithmetic number, because the mean of its divisors is an integer number (82772976).

Almost surely, 2^1201200021 is an apocalyptic number.

It is an amenable number.

1201200021 is a deficient number, since it is larger than the sum of its proper divisors (785351403).

1201200021 is a wasteful number, since it uses less digits than its factorization.

1201200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34801 (or 34798 counting only the distinct ones).

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

The square root of 1201200021 is about 34658.3326344474. The cubic root of 1201200021 is about 1063.0126768928.

Adding to 1201200021 its reverse (1200021021), we get a palindrome (2401221042).

The spelling of 1201200021 in words is "one billion, two hundred one million, two hundred thousand, twenty-one".