1201121556 has 24 divisors (see below), whose sum is σ = 2950123680. Its totient is φ = 379301472.

The previous prime is 1201121549. The next prime is 1201121557. The reversal of 1201121556 is 6551211021.

It is a super-2 number, since 2×1201121556² = 2885385984575722272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201121557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2633811 + ... + 2634266.

It is an arithmetic number, because the mean of its divisors is an integer number (122921820).

Almost surely, 2^1201121556 is an apocalyptic number.

It is an amenable number.

1201121556 is an abundant number, since it is smaller than the sum of its proper divisors (1749002124).

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

1201121556 is a wasteful number, since it uses less digits than its factorization.

1201121556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5268103 (or 5268101 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 24.

The square root of 1201121556 is about 34657.2006370970. The cubic root of 1201121556 is about 1062.9895302881.

Adding to 1201121556 its reverse (6551211021), we get a palindrome (7752332577).

The spelling of 1201121556 in words is "one billion, two hundred one million, one hundred twenty-one thousand, five hundred fifty-six".