2181963636 has 48 divisors (see below), whose sum is σ = 5662063680. Its totient is φ = 726662880.

The previous prime is 2181963611. The next prime is 2181963653. The reversal of 2181963636 is 6363691812.

2181963636 is a `hidden beast` number, since 2 + 1 + 8 + 1 + 9 + 6 + 3 + 636 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 2181963591 and 2181963600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118995 + ... + 136101.

It is an arithmetic number, because the mean of its divisors is an integer number (117959660).

Almost surely, 2^2181963636 is an apocalyptic number.

It is an amenable number.

2181963636 is an abundant number, since it is smaller than the sum of its proper divisors (3480100044).

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

2181963636 is a wasteful number, since it uses less digits than its factorization.

2181963636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18301 (or 18293 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 2181963636 is about 46711.4936177382. The cubic root of 2181963636 is about 1297.0274559754.

The spelling of 2181963636 in words is "two billion, one hundred eighty-one million, nine hundred sixty-three thousand, six hundred thirty-six".