21558012727680 has 4096 divisors, whose sum is σ = 96881295974400. Its totient is φ = 4514807808000.

The previous prime is 21558012727663. The next prime is 21558012727697. The reversal of 21558012727680 is 8672721085512.

It is a happy number.

21558012727680 is a `hidden beast` number, since 2 + 1 + 558 + 0 + 1 + 2 + 7 + 2 + 7 + 6 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (21558012727663) and next prime (21558012727697).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 303633982045 + ... + 303633982115.

It is an arithmetic number, because the mean of its divisors is an integer number (23652660150).

Almost surely, 2^{21558012727680} is an apocalyptic number.

21558012727680 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 21558012727680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48440647987200).

21558012727680 is an abundant number, since it is smaller than the sum of its proper divisors (75323283246720).

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

21558012727680 is a wasteful number, since it uses less digits than its factorization.

21558012727680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 3763200, while the sum is 54.

The spelling of 21558012727680 in words is "twenty-one trillion, five hundred fifty-eight billion, twelve million, seven hundred twenty-seven thousand, six hundred eighty".