21040331240 has 32 divisors (see below), whose sum is σ = 47443034880. Its totient is φ = 8397947712.

The previous prime is 21040331183. The next prime is 21040331287. The reversal of 21040331240 is 4213304012.

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 (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 549524 + ... + 586563.

It is an arithmetic number, because the mean of its divisors is an integer number (1482594840).

Almost surely, 2^21040331240 is an apocalyptic number.

21040331240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21040331240 is an abundant number, since it is smaller than the sum of its proper divisors (26402703640).

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

21040331240 is a wasteful number, since it uses less digits than its factorization.

21040331240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136561 (or 1136557 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21040331240 its reverse (4213304012), we get a palindrome (25253635252).

The spelling of 21040331240 in words is "twenty-one billion, forty million, three hundred thirty-one thousand, two hundred forty".