21254562664500 has 384 divisors, whose sum is σ = 68325155458560. Its totient is φ = 5091379200000.

The previous prime is 21254562664453. The next prime is 21254562664541. The reversal of 21254562664500 is 546626545212.

It is a self number, because there is not a number n which added to its sum of digits gives 21254562664500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 848235972 + ... + 848261028.

It is an arithmetic number, because the mean of its divisors is an integer number (177930092340).

Almost surely, 2^{21254562664500} is an apocalyptic number.

21254562664500 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 21254562664500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34162577729280).

21254562664500 is an abundant number, since it is smaller than the sum of its proper divisors (47070592794060).

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

21254562664500 is a wasteful number, since it uses less digits than its factorization.

21254562664500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25700 (or 25688 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 48.

The spelling of 21254562664500 in words is "twenty-one trillion, two hundred fifty-four billion, five hundred sixty-two million, six hundred sixty-four thousand, five hundred".