21017990048 has 96 divisors (see below), whose sum is σ = 45998850240. Its totient is φ = 9373224960.

The previous prime is 21017990047. The next prime is 21017990083. The reversal of 21017990048 is 84009971012.

It is a junction number, because it is equal to n+sod(n) for n = 21017989987 and 21017990014.

It is not an unprimeable number, because it can be changed into a prime (21017990041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6342440 + ... + 6345752.

It is an arithmetic number, because the mean of its divisors is an integer number (479154690).

Almost surely, 2^21017990048 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21017990048, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22999425120).

21017990048 is an abundant number, since it is smaller than the sum of its proper divisors (24980860192).

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

21017990048 is a wasteful number, since it uses less digits than its factorization.

21017990048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3670 (or 3662 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 41.

The spelling of 21017990048 in words is "twenty-one billion, seventeen million, nine hundred ninety thousand, forty-eight".