21063605357440 has 128 divisors (see below), whose sum is σ = 50723761576320. Its totient is φ = 8363995299840.

The previous prime is 21063605357419. The next prime is 21063605357479. The reversal of 21063605357440 is 4475350636012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47974105 + ... + 48411175.

It is an arithmetic number, because the mean of its divisors is an integer number (396279387315).

Almost surely, 2^{21063605357440} is an apocalyptic number.

21063605357440 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 21063605357440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25361880788160).

21063605357440 is an abundant number, since it is smaller than the sum of its proper divisors (29660156218880).

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

21063605357440 is a wasteful number, since it uses less digits than its factorization.

21063605357440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437640 (or 437628 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 46.

The spelling of 21063605357440 in words is "twenty-one trillion, sixty-three billion, six hundred five million, three hundred fifty-seven thousand, four hundred forty".