21004075008 has 900 divisors, whose sum is σ = 81357839640. Its totient is φ = 5350883328.

The previous prime is 21004075007. The next prime is 21004075097. The reversal of 21004075008 is 80057040012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004075007) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1105477623 + ... + 1105477641.

Almost surely, 2^21004075008 is an apocalyptic number.

21004075008 is a gapful number since it is divisible by the number (28) 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 21004075008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40678919820).

21004075008 is an abundant number, since it is smaller than the sum of its proper divisors (60353764632).

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

21004075008 is an equidigital number, since it uses as much as digits as its factorization.

21004075008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The spelling of 21004075008 in words is "twenty-one billion, four million, seventy-five thousand, eight".