20511671205204 has 144 divisors (see below), whose sum is σ = 54580918392000. Its totient is φ = 6485406842880.

The previous prime is 20511671205173. The next prime is 20511671205251. The reversal of 20511671205204 is 40250217611502.

20511671205204 is a `hidden beast` number, since 2 + 0 + 5 + 1 + 1 + 6 + 7 + 120 + 520 + 4 = 666.

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 polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 96661332 + ... + 96873300.

It is an arithmetic number, because the mean of its divisors is an integer number (379034155500).

Almost surely, 2^{20511671205204} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20511671205204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27290459196000).

20511671205204 is an abundant number, since it is smaller than the sum of its proper divisors (34069247186796).

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

20511671205204 is a wasteful number, since it uses less digits than its factorization.

20511671205204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213638 (or 213633 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

Adding to 20511671205204 its reverse (40250217611502), we get a palindrome (60761888816706).

The spelling of 20511671205204 in words is "twenty trillion, five hundred eleven billion, six hundred seventy-one million, two hundred five thousand, two hundred four".