20538261504 has 340 divisors, whose sum is σ = 63374925636. Its totient is φ = 6624903168.

The previous prime is 20538261481. The next prime is 20538261511. The reversal of 20538261504 is 40516283502.

20538261504 is a `hidden beast` number, since 2 + 0 + 5 + 38 + 2 + 615 + 0 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 13271040000 + 7267221504 = 115200^2 + 85248^2 .

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 19 ways as a sum of consecutive naturals, for example, 281346012 + ... + 281346084.

Almost surely, 2^20538261504 is an apocalyptic number.

20538261504 is a gapful number since it is divisible by the number (24) 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 20538261504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31687462818).

20538261504 is an abundant number, since it is smaller than the sum of its proper divisors (42836664132).

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

20538261504 is an frugal number, since it uses more digits than its factorization.

20538261504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 20538261504 in words is "twenty billion, five hundred thirty-eight million, two hundred sixty-one thousand, five hundred four".