21011004440 has 32 divisors (see below), whose sum is σ = 47940608160. Its totient is φ = 8286028800.

The previous prime is 21011004437. The next prime is 21011004449. The reversal of 21011004440 is 4440011012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011004449) 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, 3696281 + ... + 3701960.

It is an arithmetic number, because the mean of its divisors is an integer number (1498144005).

Almost surely, 2^21011004440 is an apocalyptic number.

21011004440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011004440 is an abundant number, since it is smaller than the sum of its proper divisors (26929603720).

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

21011004440 is a wasteful number, since it uses less digits than its factorization.

21011004440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7398323 (or 7398319 counting only the distinct ones).

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

Adding to 21011004440 its reverse (4440011012), we get a palindrome (25451015452).

The spelling of 21011004440 in words is "twenty-one billion, eleven million, four thousand, four hundred forty".