21430220 has 24 divisors (see below), whose sum is σ = 51432864. Its totient is φ = 7347456.

The previous prime is 21430193. The next prime is 21430229. The reversal of 21430220 is 2203412.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21430195 and 21430204.

It is not an unprimeable number, because it can be changed into a prime (21430229) 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, 76397 + ... + 76676.

It is an arithmetic number, because the mean of its divisors is an integer number (2143036).

Almost surely, 2^21430220 is an apocalyptic number.

21430220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21430220 is an abundant number, since it is smaller than the sum of its proper divisors (30002644).

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

21430220 is a wasteful number, since it uses less digits than its factorization.

21430220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153089 (or 153087 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21430220 is about 4629.2785615039. The cubic root of 21430220 is about 277.7637348753.

Adding to 21430220 its reverse (2203412), we get a palindrome (23633632).

The spelling of 21430220 in words is "twenty-one million, four hundred thirty thousand, two hundred twenty".