21296481990 has 256 divisors, whose sum is σ = 62671601664. Its totient is φ = 4528742400.

The previous prime is 21296481923. The next prime is 21296482001. The reversal of 21296481990 is 9918469212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 19483884 + ... + 19484976.

It is an arithmetic number, because the mean of its divisors is an integer number (244810944).

Almost surely, 2^21296481990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21296481990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31335800832).

21296481990 is an abundant number, since it is smaller than the sum of its proper divisors (41375119674).

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

21296481990 is a wasteful number, since it uses less digits than its factorization.

21296481990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255.

The product of its (nonzero) digits is 559872, while the sum is 51.

The spelling of 21296481990 in words is "twenty-one billion, two hundred ninety-six million, four hundred eighty-one thousand, nine hundred ninety".