1213864236 has 144 divisors (see below), whose sum is σ = 3381094080. Its totient is φ = 364953600.

The previous prime is 1213864189. The next prime is 1213864237. The reversal of 1213864236 is 6324683121.

1213864236 is a `hidden beast` number, since 1 + 2 + 1 + 3 + 8 + 642 + 3 + 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 1213864236.

It is not an unprimeable number, because it can be changed into a prime (1213864237) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6289356 + ... + 6289548.

It is an arithmetic number, because the mean of its divisors is an integer number (23479820).

Almost surely, 2^1213864236 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 1213864236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1690547040).

1213864236 is an abundant number, since it is smaller than the sum of its proper divisors (2167229844).

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

1213864236 is a wasteful number, since it uses less digits than its factorization.

1213864236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456 (or 451 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 1213864236 is about 34840.5544731998. The cubic root of 1213864236 is about 1066.7353945733.

The spelling of 1213864236 in words is "one billion, two hundred thirteen million, eight hundred sixty-four thousand, two hundred thirty-six".