20871671040 has 216 divisors, whose sum is σ = 78779177568. Its totient is φ = 5059768320.

The previous prime is 20871670999. The next prime is 20871671047. The reversal of 20871671040 is 4017617802.

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 = 20871670986 and 20871671004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20871671047) 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 23 ways as a sum of consecutive naturals, for example, 44367 + ... + 209073.

Almost surely, 2^20871671040 is an apocalyptic number.

20871671040 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 20871671040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39389588784).

20871671040 is an abundant number, since it is smaller than the sum of its proper divisors (57907506528).

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

20871671040 is a wasteful number, since it uses less digits than its factorization.

20871671040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164745 (or 164728 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The spelling of 20871671040 in words is "twenty billion, eight hundred seventy-one million, six hundred seventy-one thousand, forty".