1201215643 has 4 divisors (see below), whose sum is σ = 1212236080. Its totient is φ = 1190195208.

The previous prime is 1201215637. The next prime is 1201215647. The reversal of 1201215643 is 3465121021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3465121021 = 2857 ⋅1212853.

It is a cyclic number.

It is not a de Polignac number, because 1201215643 - 2⁵ = 1201215611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1201215647) 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, 5510055 + ... + 5510272.

It is an arithmetic number, because the mean of its divisors is an integer number (303059020).

Almost surely, 2^1201215643 is an apocalyptic number.

1201215643 is a deficient number, since it is larger than the sum of its proper divisors (11020437).

1201215643 is a wasteful number, since it uses less digits than its factorization.

1201215643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11020436.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 1201215643 is about 34658.5580052027. The cubic root of 1201215643 is about 1063.0172851489.

Adding to 1201215643 its reverse (3465121021), we get a palindrome (4666336664).

The spelling of 1201215643 in words is "one billion, two hundred one million, two hundred fifteen thousand, six hundred forty-three".