21054413240 has 128 divisors (see below), whose sum is σ = 55862784000. Its totient is φ = 6992414208.

The previous prime is 21054413203. The next prime is 21054413243. The reversal of 21054413240 is 4231445012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054413243) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 1163381 + ... + 1181339.

It is an arithmetic number, because the mean of its divisors is an integer number (436428000).

Almost surely, 2^21054413240 is an apocalyptic number.

21054413240 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 21054413240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27931392000).

21054413240 is an abundant number, since it is smaller than the sum of its proper divisors (34808370760).

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

21054413240 is a wasteful number, since it uses less digits than its factorization.

21054413240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18109 (or 18105 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21054413240 its reverse (4231445012), we get a palindrome (25285858252).

The spelling of 21054413240 in words is "twenty-one billion, fifty-four million, four hundred thirteen thousand, two hundred forty".