20613994236 has 168 divisors, whose sum is σ = 60910284288. Its totient is φ = 6044868000.

The previous prime is 20613994213. The next prime is 20613994243. The reversal of 20613994236 is 63249931602.

20613994236 is a `hidden beast` number, since 2 + 0 + 613 + 9 + 9 + 4 + 23 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20613994191 and 20613994200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 983991 + ... + 1004721.

It is an arithmetic number, because the mean of its divisors is an integer number (362561216).

Almost surely, 2^20613994236 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 20613994236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30455142144).

20613994236 is an abundant number, since it is smaller than the sum of its proper divisors (40296290052).

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

20613994236 is a wasteful number, since it uses less digits than its factorization.

20613994236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20795 (or 20778 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 45.

The spelling of 20613994236 in words is "twenty billion, six hundred thirteen million, nine hundred ninety-four thousand, two hundred thirty-six".