21099297897600 has 384 divisors, whose sum is σ = 75082430666880. Its totient is φ = 5176963891200.

The previous prime is 21099297897511. The next prime is 21099297897631. The reversal of 21099297897600 is 679879299012.

It is a tau number, because it is divible by the number of its divisors (384).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 38540992 + ... + 39084608.

It is an arithmetic number, because the mean of its divisors is an integer number (195527163195).

Almost surely, 2^{21099297897600} is an apocalyptic number.

21099297897600 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 21099297897600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37541215333440).

21099297897600 is an abundant number, since it is smaller than the sum of its proper divisors (53983132769280).

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

21099297897600 is a wasteful number, since it uses less digits than its factorization.

21099297897600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543968 (or 543951 counting only the distinct ones).

The product of its (nonzero) digits is 61725888, while the sum is 69.

The spelling of 21099297897600 in words is "twenty-one trillion, ninety-nine billion, two hundred ninety-seven million, eight hundred ninety-seven thousand, six hundred".