20101645872 has 240 divisors, whose sum is σ = 70309404672. Its totient is φ = 5208468480.

The previous prime is 20101645867. The next prime is 20101645913. The reversal of 20101645872 is 27854610102.

20101645872 is a `hidden beast` number, since 2 + 0 + 1 + 0 + 1 + 645 + 8 + 7 + 2 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5065233 + ... + 5069199.

Almost surely, 2^20101645872 is an apocalyptic number.

20101645872 is a gapful number since it is divisible by the number (22) 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 20101645872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35154702336).

20101645872 is an abundant number, since it is smaller than the sum of its proper divisors (50207758800).

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

20101645872 is a wasteful number, since it uses less digits than its factorization.

20101645872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4456 (or 4447 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The spelling of 20101645872 in words is "twenty billion, one hundred one million, six hundred forty-five thousand, eight hundred seventy-two".