21011440220 has 12 divisors (see below), whose sum is σ = 44124024504. Its totient is φ = 8404576080.

The previous prime is 21011440141. The next prime is 21011440253. The reversal of 21011440220 is 2204411012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525285986 + ... + 525286025.

It is an arithmetic number, because the mean of its divisors is an integer number (3677002042).

Almost surely, 2^21011440220 is an apocalyptic number.

21011440220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011440220 is an abundant number, since it is smaller than the sum of its proper divisors (23112584284).

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

21011440220 is a wasteful number, since it uses less digits than its factorization.

21011440220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050572020 (or 1050572018 counting only the distinct ones).

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

Adding to 21011440220 its reverse (2204411012), we get a palindrome (23215851232).

The spelling of 21011440220 in words is "twenty-one billion, eleven million, four hundred forty thousand, two hundred twenty".