21025987190208 has 2016 divisors, whose sum is σ = 89137909486080. Its totient is φ = 4821438504960.

The previous prime is 21025987190149. The next prime is 21025987190239. The reversal of 21025987190208 is 80209178952012.

21025987190208 is a `hidden beast` number, since 2 + 10 + 2 + 598 + 7 + 19 + 0 + 20 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

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 287 ways as a sum of consecutive naturals, for example, 2506371678 + ... + 2506380066.

It is an arithmetic number, because the mean of its divisors is an integer number (44215232880).

Almost surely, 2^{21025987190208} is an apocalyptic number.

21025987190208 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 21025987190208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44568954743040).

21025987190208 is an abundant number, since it is smaller than the sum of its proper divisors (68111922295872).

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

21025987190208 is a wasteful number, since it uses less digits than its factorization.

21025987190208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8477 (or 8448 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 21025987190208 in words is "twenty-one trillion, twenty-five billion, nine hundred eighty-seven million, one hundred ninety thousand, two hundred eight".