21021345879744 has 224 divisors, whose sum is σ = 67506995344896. Its totient is φ = 5635718922240.

The previous prime is 21021345879719. The next prime is 21021345879811. The reversal of 21021345879744 is 44797854312012.

It is a tau number, because it is divible by the number of its divisors (224).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6172882 + ... + 8952494.

Almost surely, 2^{21021345879744} is an apocalyptic number.

21021345879744 is a gapful number since it is divisible by the number (24) 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 21021345879744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33753497672448).

21021345879744 is an abundant number, since it is smaller than the sum of its proper divisors (46485649465152).

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

21021345879744 is a wasteful number, since it uses less digits than its factorization.

21021345879744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2779983 (or 2779973 counting only the distinct ones).

The product of its (nonzero) digits is 13547520, while the sum is 57.

The spelling of 21021345879744 in words is "twenty-one trillion, twenty-one billion, three hundred forty-five million, eight hundred seventy-nine thousand, seven hundred forty-four".