20129120640 has 384 divisors, whose sum is σ = 74038536000. Its totient is φ = 5021761536.

The previous prime is 20129120633. The next prime is 20129120647. The reversal of 20129120640 is 4602192102.

20129120640 is a `hidden beast` number, since 2 + 0 + 1 + 2 + 9 + 12 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (20129120633) and next prime (20129120647).

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20129120647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19485564 + ... + 19486596.

Almost surely, 2^20129120640 is an apocalyptic number.

20129120640 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 20129120640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37019268000).

20129120640 is an abundant number, since it is smaller than the sum of its proper divisors (53909415360).

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

20129120640 is a wasteful number, since it uses less digits than its factorization.

20129120640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1274 (or 1259 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The spelling of 20129120640 in words is "twenty billion, one hundred twenty-nine million, one hundred twenty thousand, six hundred forty".