20129665263840 has 384 divisors, whose sum is σ = 77080279933440. Its totient is φ = 4865851699200.

The previous prime is 20129665263821. The next prime is 20129665263893. The reversal of 20129665263840 is 4836256692102.

20129665263840 is a `hidden beast` number, since 2 + 0 + 1 + 29 + 66 + 526 + 38 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15879060 + ... + 17099820.

It is an arithmetic number, because the mean of its divisors is an integer number (200729895660).

Almost surely, 2^{20129665263840} is an apocalyptic number.

20129665263840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20129665263840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38540139966720).

20129665263840 is an abundant number, since it is smaller than the sum of its proper divisors (56950614669600).

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

20129665263840 is a wasteful number, since it uses less digits than its factorization.

20129665263840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1221143 (or 1221129 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 54.

The spelling of 20129665263840 in words is "twenty trillion, one hundred twenty-nine billion, six hundred sixty-five million, two hundred sixty-three thousand, eight hundred forty".