20005539840 has 1248 divisors, whose sum is σ = 87849457920. Its totient is φ = 4282122240.

The previous prime is 20005539839. The next prime is 20005539889. The reversal of 20005539840 is 4893550002.

20005539840 is a `hidden beast` number, since 20 + 0 + 0 + 553 + 9 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1248).

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 = 20005539795 and 20005539804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 869806069 + ... + 869806091.

Almost surely, 2^20005539840 is an apocalyptic number.

20005539840 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 20005539840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43924728960).

20005539840 is an abundant number, since it is smaller than the sum of its proper divisors (67843918080).

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

20005539840 is a wasteful number, since it uses less digits than its factorization.

20005539840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 20005539840 in words is "twenty billion, five million, five hundred thirty-nine thousand, eight hundred forty".