21298445355990 has 384 divisors, whose sum is σ = 60505794160128. Its totient is φ = 4754378280960.

The previous prime is 21298445355989. The next prime is 21298445356007. The reversal of 21298445355990 is 9955354489212.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5761005822 + ... + 5761009518.

It is an arithmetic number, because the mean of its divisors is an integer number (157567172292).

Almost surely, 2^{21298445355990} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21298445355990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30252897080064).

21298445355990 is an abundant number, since it is smaller than the sum of its proper divisors (39207348804138).

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

21298445355990 is a wasteful number, since it uses less digits than its factorization.

21298445355990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5100 (or 5081 counting only the distinct ones).

The product of its (nonzero) digits is 139968000, while the sum is 66.

The spelling of 21298445355990 in words is "twenty-one trillion, two hundred ninety-eight billion, four hundred forty-five million, three hundred fifty-five thousand, nine hundred ninety".