21501555650160 has 320 divisors, whose sum is σ = 71180496728064. Its totient is φ = 5359404441600.

The previous prime is 21501555650153. The next prime is 21501555650161. The reversal of 21501555650160 is 6105655510512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21501555650161) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 37428295 + ... + 37998425.

Almost surely, 2^{21501555650160} is an apocalyptic number.

21501555650160 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 21501555650160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35590248364032).

21501555650160 is an abundant number, since it is smaller than the sum of its proper divisors (49678941077904).

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

21501555650160 is a wasteful number, since it uses less digits than its factorization.

21501555650160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 570352 (or 570346 counting only the distinct ones).

The product of its (nonzero) digits is 225000, while the sum is 42.

The spelling of 21501555650160 in words is "twenty-one trillion, five hundred one billion, five hundred fifty-five million, six hundred fifty thousand, one hundred sixty".