21421120104 has 192 divisors, whose sum is σ = 63698019840. Its totient is φ = 6482488320.

The previous prime is 21421120093. The next prime is 21421120153. The reversal of 21421120104 is 40102112412.

21421120104 is a `hidden beast` number, since 21 + 421 + 120 + 104 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 2507889 + ... + 2516415.

It is an arithmetic number, because the mean of its divisors is an integer number (331760520).

Almost surely, 2^21421120104 is an apocalyptic number.

21421120104 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 21421120104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31849009920).

21421120104 is an abundant number, since it is smaller than the sum of its proper divisors (42276899736).

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

21421120104 is a wasteful number, since it uses less digits than its factorization.

21421120104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8640 (or 8633 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21421120104 its reverse (40102112412), we get a palindrome (61523232516).

The spelling of 21421120104 in words is "twenty-one billion, four hundred twenty-one million, one hundred twenty thousand, one hundred four".