2105421240 has 128 divisors (see below), whose sum is σ = 6856335360. Its totient is φ = 514128384.

The previous prime is 2105421239. The next prime is 2105421247. The reversal of 2105421240 is 421245012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105421247) 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, 192807 + ... + 203433.

It is an arithmetic number, because the mean of its divisors is an integer number (53565120).

Almost surely, 2^2105421240 is an apocalyptic number.

2105421240 is a gapful number since it is divisible by the number (20) 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 2105421240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3428167680).

2105421240 is an abundant number, since it is smaller than the sum of its proper divisors (4750914120).

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

2105421240 is a wasteful number, since it uses less digits than its factorization.

2105421240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10781 (or 10777 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 2105421240 is about 45884.8694015794. The cubic root of 2105421240 is about 1281.6801747611.

Adding to 2105421240 its reverse (421245012), we get a palindrome (2526666252).

The spelling of 2105421240 in words is "two billion, one hundred five million, four hundred twenty-one thousand, two hundred forty".