21549770733720 has 384 divisors, whose sum is σ = 68686804569600. Its totient is φ = 5407155443712.

The previous prime is 21549770733719. The next prime is 21549770733727. The reversal of 21549770733720 is 2733707794512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21549770733727) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3440803309 + ... + 3440809571.

It is an arithmetic number, because the mean of its divisors is an integer number (178871886900).

Almost surely, 2^{21549770733720} is an apocalyptic number.

21549770733720 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 21549770733720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34343402284800).

21549770733720 is an abundant number, since it is smaller than the sum of its proper divisors (47137033835880).

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

21549770733720 is a wasteful number, since it uses less digits than its factorization.

21549770733720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7199 (or 7172 counting only the distinct ones).

The product of its (nonzero) digits is 15558480, while the sum is 57.

The spelling of 21549770733720 in words is "twenty-one trillion, five hundred forty-nine billion, seven hundred seventy million, seven hundred thirty-three thousand, seven hundred twenty".