21430441956 has 96 divisors (see below), whose sum is σ = 62387942400. Its totient is φ = 5562345600.

The previous prime is 21430441897. The next prime is 21430441957. The reversal of 21430441956 is 65914403412.

It is not an unprimeable number, because it can be changed into a prime (21430441957) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1407070 + ... + 1422218.

It is an arithmetic number, because the mean of its divisors is an integer number (649874400).

Almost surely, 2^21430441956 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 21430441956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31193971200).

21430441956 is an abundant number, since it is smaller than the sum of its proper divisors (40957500444).

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

21430441956 is a wasteful number, since it uses less digits than its factorization.

21430441956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16705 (or 16703 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21430441956 in words is "twenty-one billion, four hundred thirty million, four hundred forty-one thousand, nine hundred fifty-six".