1201115656 has 16 divisors (see below), whose sum is σ = 2425329900. Its totient is φ = 554361024.

The previous prime is 1201115639. The next prime is 1201115693. The reversal of 1201115656 is 6565111021.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1156680100 + 44435556 = 34010^2 + 6666^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5774491 + ... + 5774698.

Almost surely, 2^1201115656 is an apocalyptic number.

It is an amenable number.

1201115656 is an abundant number, since it is smaller than the sum of its proper divisors (1224214244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1201115656 is a wasteful number, since it uses less digits than its factorization.

1201115656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11549208 (or 11549204 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 1201115656 is about 34657.1155175961. The cubic root of 1201115656 is about 1062.9877897903.

Adding to 1201115656 its reverse (6565111021), we get a palindrome (7766226677).

The spelling of 1201115656 in words is "one billion, two hundred one million, one hundred fifteen thousand, six hundred fifty-six".