21027285661500 has 288 divisors, whose sum is σ = 67361178620736. Its totient is φ = 5520546662400.

The previous prime is 21027285661483. The next prime is 21027285661573. The reversal of 21027285661500 is 516658272012.

21027285661500 is a `hidden beast` number, since 2 + 1 + 0 + 2 + 7 + 2 + 85 + 6 + 61 + 500 = 666.

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 95 ways as a sum of consecutive naturals, for example, 576751272 + ... + 576787728.

It is an arithmetic number, because the mean of its divisors is an integer number (233892981322).

Almost surely, 2^{21027285661500} is an apocalyptic number.

21027285661500 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 21027285661500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33680589310368).

21027285661500 is an abundant number, since it is smaller than the sum of its proper divisors (46333892959236).

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

21027285661500 is a wasteful number, since it uses less digits than its factorization.

21027285661500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38462 (or 38447 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 21027285661500 in words is "twenty-one trillion, twenty-seven billion, two hundred eighty-five million, six hundred sixty-one thousand, five hundred".