21420441042 has 192 divisors, whose sum is σ = 60570115200. Its totient is φ = 4958392320.

The previous prime is 21420441037. The next prime is 21420441047. The reversal of 21420441042 is 24014402412.

It is an interprime number because it is at equal distance from previous prime (21420441037) and next prime (21420441047).

It is not an unprimeable number, because it can be changed into a prime (21420441047) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1210434 + ... + 1228002.

It is an arithmetic number, because the mean of its divisors is an integer number (315469350).

Almost surely, 2^21420441042 is an apocalyptic number.

21420441042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21420441042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30285057600).

21420441042 is an abundant number, since it is smaller than the sum of its proper divisors (39149674158).

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

21420441042 is a wasteful number, since it uses less digits than its factorization.

21420441042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17641 (or 17634 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21420441042 its reverse (24014402412), we get a palindrome (45434843454).

The spelling of 21420441042 in words is "twenty-one billion, four hundred twenty million, four hundred forty-one thousand, forty-two".