1212163956 has 72 divisors (see below), whose sum is σ = 3170017760. Its totient is φ = 390246336.

The previous prime is 1212163951. The next prime is 1212163987. The reversal of 1212163956 is 6593612121.

1212163956 is a `hidden beast` number, since 1 + 2 + 12 + 1 + 639 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1212163956.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212163951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 181875 + ... + 188421.

Almost surely, 2^1212163956 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212163956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1585008880).

1212163956 is an abundant number, since it is smaller than the sum of its proper divisors (1957853804).

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

1212163956 is a wasteful number, since it uses less digits than its factorization.

1212163956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6733 (or 6728 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 1212163956 is about 34816.1450479515. The cubic root of 1212163956 is about 1066.2370971218.

The spelling of 1212163956 in words is "one billion, two hundred twelve million, one hundred sixty-three thousand, nine hundred fifty-six".