20818256612400 has 960 divisors, whose sum is σ = 82780201728000. Its totient is φ = 4936113561600.

The previous prime is 20818256612399. The next prime is 20818256612423. The reversal of 20818256612400 is 421665281802.

20818256612400 is a `hidden beast` number, since 2 + 0 + 8 + 1 + 8 + 25 + 6 + 612 + 4 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 191 ways as a sum of consecutive naturals, for example, 454732711 + ... + 454778489.

It is an arithmetic number, because the mean of its divisors is an integer number (86229376800).

Almost surely, 2^{20818256612400} is an apocalyptic number.

20818256612400 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 20818256612400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41390100864000).

20818256612400 is an abundant number, since it is smaller than the sum of its proper divisors (61961945115600).

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

20818256612400 is a wasteful number, since it uses less digits than its factorization.

20818256612400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45939 (or 45922 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 20818256612400 in words is "twenty trillion, eight hundred eighteen billion, two hundred fifty-six million, six hundred twelve thousand, four hundred".