21062220 has 24 divisors (see below), whose sum is σ = 58974384. Its totient is φ = 5616576.

The previous prime is 21062219. The next prime is 21062257. The reversal of 21062220 is 2226012.

It is a super-2 number, since 2×21062220² = 887234222656800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21062220.

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, 175459 + ... + 175578.

It is an arithmetic number, because the mean of its divisors is an integer number (2457266).

Almost surely, 2^21062220 is an apocalyptic number.

21062220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21062220 is an abundant number, since it is smaller than the sum of its proper divisors (37912164).

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

21062220 is a wasteful number, since it uses less digits than its factorization.

21062220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351049 (or 351047 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21062220 is about 4589.3594324263. The cubic root of 21062220 is about 276.1646255839.

Adding to 21062220 its reverse (2226012), we get a palindrome (23288232).

The spelling of 21062220 in words is "twenty-one million, sixty-two thousand, two hundred twenty".