20381621206464 has 336 divisors, whose sum is σ = 69607745805312. Its totient is φ = 5580573014016.

The previous prime is 20381621206459. The next prime is 20381621206477. The reversal of 20381621206464 is 46460212618302.

20381621206464 is a `hidden beast` number, since 2 + 0 + 3 + 8 + 1 + 62 + 120 + 6 + 464 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

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, 8079897 + ... + 10297959.

Almost surely, 2^{20381621206464} is an apocalyptic number.

20381621206464 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 20381621206464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34803872902656).

20381621206464 is an abundant number, since it is smaller than the sum of its proper divisors (49226124598848).

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

20381621206464 is a wasteful number, since it uses less digits than its factorization.

20381621206464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2218184 (or 2218171 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 20381621206464 in words is "twenty trillion, three hundred eighty-one billion, six hundred twenty-one million, two hundred six thousand, four hundred sixty-four".