21480375 has 64 divisors (see below), whose sum is σ = 41932800. Its totient is φ = 9760800.

The previous prime is 21480353. The next prime is 21480379. The reversal of 21480375 is 57308412.

It is not a de Polignac number, because 21480375 - 2⁵ = 21480343 is a prime.

It is a super-2 number, since 2×21480375² = 922813020281250, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21480379) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 128542 + ... + 128708.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^21480375 is an apocalyptic number.

21480375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21480375 is a deficient number, since it is larger than the sum of its proper divisors (20452425).

21480375 is an equidigital number, since it uses as much as digits as its factorization.

21480375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21480375 is about 4634.6925464371. The cubic root of 21480375 is about 277.9802575563.

Adding to 21480375 its reverse (57308412), we get a palindrome (78788787).

The spelling of 21480375 in words is "twenty-one million, four hundred eighty thousand, three hundred seventy-five".