20851801344 has 216 divisors, whose sum is σ = 65765062272. Its totient is φ = 6301532160.

The previous prime is 20851801337. The next prime is 20851801393. The reversal of 20851801344 is 44310815802.

20851801344 is a `hidden beast` number, since 2 + 0 + 8 + 518 + 0 + 134 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20851801299 and 20851801308.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11733384 + ... + 11735160.

Almost surely, 2^20851801344 is an apocalyptic number.

20851801344 is a gapful number since it is divisible by the number (24) 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 20851801344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32882531136).

20851801344 is an abundant number, since it is smaller than the sum of its proper divisors (44913260928).

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

20851801344 is a wasteful number, since it uses less digits than its factorization.

20851801344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2273 (or 2256 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The spelling of 20851801344 in words is "twenty billion, eight hundred fifty-one million, eight hundred one thousand, three hundred forty-four".