21000214240 has 48 divisors (see below), whose sum is σ = 52531425072. Its totient is φ = 7905961984.

The previous prime is 21000214231. The next prime is 21000214247. The reversal of 21000214240 is 4241200012.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000214247) 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 7 ways as a sum of consecutive naturals, for example, 3857614 + ... + 3863053.

It is an arithmetic number, because the mean of its divisors is an integer number (1094404689).

Almost surely, 2^21000214240 is an apocalyptic number.

21000214240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000214240 is an abundant number, since it is smaller than the sum of its proper divisors (31531210832).

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

21000214240 is a wasteful number, since it uses less digits than its factorization.

21000214240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7720699 (or 7720691 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21000214240 its reverse (4241200012), we get a palindrome (25241414252).

The spelling of 21000214240 in words is "twenty-one billion, two hundred fourteen thousand, two hundred forty".