21219220 has 24 divisors (see below), whose sum is σ = 48611808. Its totient is φ = 7716000.

The previous prime is 21219203. The next prime is 21219259. The reversal of 21219220 is 2291212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48006 + ... + 48445.

It is an arithmetic number, because the mean of its divisors is an integer number (2025492).

Almost surely, 2^21219220 is an apocalyptic number.

21219220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21219220 is an abundant number, since it is smaller than the sum of its proper divisors (27392588).

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

21219220 is a wasteful number, since it uses less digits than its factorization.

21219220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96471 (or 96469 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21219220 is about 4606.4324590729. The cubic root of 21219220 is about 276.8491143483.

It can be divided in two parts, 212192 and 20, that added together give a palindrome (212212).

The spelling of 21219220 in words is "twenty-one million, two hundred nineteen thousand, two hundred twenty".