20521409455008 has 648 divisors, whose sum is σ = 77862417351264. Its totient is φ = 5098477063680.

The previous prime is 20521409454947. The next prime is 20521409455013. The reversal of 20521409455008 is 80055490412502.

20521409455008 is a `hidden beast` number, since 2 + 0 + 5 + 2 + 1 + 4 + 0 + 94 + 550 + 0 + 8 = 666.

It is a super-2 number, since 2×20521409455008² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 39012435 + ... + 39534957.

It is an arithmetic number, because the mean of its divisors is an integer number (120158051468).

Almost surely, 2^{20521409455008} is an apocalyptic number.

20521409455008 is a gapful number since it is divisible by the number (28) 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 20521409455008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38931208675632).

20521409455008 is an abundant number, since it is smaller than the sum of its proper divisors (57341007896256).

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

20521409455008 is a wasteful number, since it uses less digits than its factorization.

20521409455008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522598 (or 522569 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 45.

The spelling of 20521409455008 in words is "twenty trillion, five hundred twenty-one billion, four hundred nine million, four hundred fifty-five thousand, eight".