21011342240 has 48 divisors (see below), whose sum is σ = 56730627072. Its totient is φ = 7203888384.

The previous prime is 21011342239. The next prime is 21011342267. The reversal of 21011342240 is 4224311012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9378944 + ... + 9381183.

It is an arithmetic number, because the mean of its divisors is an integer number (1181888064).

Almost surely, 2^21011342240 is an apocalyptic number.

21011342240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011342240 is an abundant number, since it is smaller than the sum of its proper divisors (35719284832).

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

21011342240 is a wasteful number, since it uses less digits than its factorization.

21011342240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18760149 (or 18760141 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21011342240 its reverse (4224311012), we get a palindrome (25235653252).

The spelling of 21011342240 in words is "twenty-one billion, eleven million, three hundred forty-two thousand, two hundred forty".