21010140440 has 16 divisors (see below), whose sum is σ = 47272816080. Its totient is φ = 8404056160.

The previous prime is 21010140433. The next prime is 21010140449. The reversal of 21010140440 is 4404101012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010140449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262626716 + ... + 262626795.

It is an arithmetic number, because the mean of its divisors is an integer number (2954551005).

Almost surely, 2^21010140440 is an apocalyptic number.

21010140440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21010140440 is an abundant number, since it is smaller than the sum of its proper divisors (26262675640).

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

21010140440 is a wasteful number, since it uses less digits than its factorization.

21010140440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525253522 (or 525253518 counting only the distinct ones).

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

Adding to 21010140440 its reverse (4404101012), we get a palindrome (25414241452).

The spelling of 21010140440 in words is "twenty-one billion, ten million, one hundred forty thousand, four hundred forty".