21387693600000 has 4536 divisors, whose sum is σ = 102203167578624. Its totient is φ = 4367001600000.

The previous prime is 21387693599983. The next prime is 21387693600011. The reversal of 21387693600000 is 639678312.

21387693600000 is a `hidden beast` number, since 2 + 1 + 38 + 7 + 6 + 9 + 3 + 600 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (4536).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 503 ways as a sum of consecutive naturals, for example, 689925599985 + ... + 689925600015.

Almost surely, 2^{21387693600000} is an apocalyptic number.

21387693600000 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 21387693600000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51101583789312).

21387693600000 is an abundant number, since it is smaller than the sum of its proper divisors (80815473978624).

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

21387693600000 is an frugal number, since it uses more digits than its factorization.

21387693600000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The spelling of 21387693600000 in words is "twenty-one trillion, three hundred eighty-seven billion, six hundred ninety-three million, six hundred thousand".