20891144160 has 120 divisors (see below), whose sum is σ = 73728375336. Its totient is φ = 5570968320.

The previous prime is 20891144159. The next prime is 20891144189. The reversal of 20891144160 is 6144119802.

20891144160 is a `hidden beast` number, since 208 + 9 + 1 + 1 + 441 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

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 19 ways as a sum of consecutive naturals, for example, 793026 + ... + 818945.

Almost surely, 2^20891144160 is an apocalyptic number.

20891144160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20891144160 is an abundant number, since it is smaller than the sum of its proper divisors (52837231176).

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

20891144160 is a wasteful number, since it uses less digits than its factorization.

20891144160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1611998 (or 1611981 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 20891144160 in words is "twenty billion, eight hundred ninety-one million, one hundred forty-four thousand, one hundred sixty".