20649638840688 has 240 divisors, whose sum is σ = 70408085844096. Its totient is φ = 5776122597120.

The previous prime is 20649638840653. The next prime is 20649638840771. The reversal of 20649638840688 is 88604883694602.

It is a happy number.

20649638840688 is a `hidden beast` number, since 2 + 0 + 6 + 4 + 9 + 63 + 88 + 406 + 88 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 18014370 + ... + 19126337.

Almost surely, 2^{20649638840688} is an apocalyptic number.

It is an amenable number.

20649638840688 is an abundant number, since it is smaller than the sum of its proper divisors (49758447003408).

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

20649638840688 is a wasteful number, since it uses less digits than its factorization.

20649638840688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37140754 (or 37140736 counting only the distinct ones).

The product of its (nonzero) digits is 764411904, while the sum is 72.

The spelling of 20649638840688 in words is "twenty trillion, six hundred forty-nine billion, six hundred thirty-eight million, eight hundred forty thousand, six hundred eighty-eight".