21230480 has 20 divisors (see below), whose sum is σ = 49361052. Its totient is φ = 8492160.

The previous prime is 21230459. The next prime is 21230483. The reversal of 21230480 is 8403212.

It can be written as a sum of positive squares in 2 ways, for example, as 10784656 + 10445824 = 3284^2 + 3232^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (21230483) 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, 132611 + ... + 132770.

Almost surely, 2^21230480 is an apocalyptic number.

21230480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21230480 is an abundant number, since it is smaller than the sum of its proper divisors (28130572).

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

21230480 is a wasteful number, since it uses less digits than its factorization.

21230480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265394 (or 265388 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21230480 is about 4607.6545009365. The cubic root of 21230480 is about 276.8980757739.

Adding to 21230480 its reverse (8403212), we get a palindrome (29633692).

The spelling of 21230480 in words is "twenty-one million, two hundred thirty thousand, four hundred eighty".