1213643736 has 240 divisors, whose sum is σ = 3756135240. Its totient is φ = 364815360.

The previous prime is 1213643731. The next prime is 1213643773. The reversal of 1213643736 is 6373463121.

1213643736 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 643 + 7 + 3 + 6 = 666.

It is a super-2 number, since 2×1213643736² = 2945862235864075392, which contains 22 as substring.

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

Its product of digits (54432) is a multiple of the sum of its prime factors (224).

It is a self number, because there is not a number n which added to its sum of digits gives 1213643736.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213643731) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 9264391 + ... + 9264521.

Almost surely, 2^1213643736 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 1213643736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1878067620).

1213643736 is an abundant number, since it is smaller than the sum of its proper divisors (2542491504).

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

1213643736 is a wasteful number, since it uses less digits than its factorization.

1213643736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 182 counting only the distinct ones).

The product of its digits is 54432, while the sum is 36.

The square root of 1213643736 is about 34837.3899137120. The cubic root of 1213643736 is about 1066.6707993763.

The spelling of 1213643736 in words is "one billion, two hundred thirteen million, six hundred forty-three thousand, seven hundred thirty-six".