21004011440 has 40 divisors (see below), whose sum is σ = 48841622448. Its totient is φ = 8400349440.

The previous prime is 21004011421. The next prime is 21004011443. The reversal of 21004011440 is 4411040012.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21004011443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 669710 + ... + 700370.

Almost surely, 2^21004011440 is an apocalyptic number.

21004011440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004011440 is an abundant number, since it is smaller than the sum of its proper divisors (27837611008).

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

21004011440 is a wasteful number, since it uses less digits than its factorization.

21004011440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39237 (or 39231 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21004011440 its reverse (4411040012), we get a palindrome (25415051452).

The spelling of 21004011440 in words is "twenty-one billion, four million, eleven thousand, four hundred forty".