21452500 has 30 divisors (see below), whose sum is σ = 46917794. Its totient is φ = 8580000.

The previous prime is 21452479. The next prime is 21452503. The reversal of 21452500 is 525412.

It can be written as a sum of positive squares in 5 ways, for example, as 16353936 + 5098564 = 4044^2 + 2258^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1791 + ... + 6790.

Almost surely, 2^21452500 is an apocalyptic number.

21452500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21452500 is an abundant number, since it is smaller than the sum of its proper divisors (25465294).

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

21452500 is an equidigital number, since it uses as much as digits as its factorization.

21452500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8605 (or 8588 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21452500 is about 4631.6843588483. The cubic root of 21452500 is about 277.8599608682.

Adding to 21452500 its reverse (525412), we get a palindrome (21977912).

It can be divided in two parts, 21452 and 500, that added together give a cube (21952 = 28³).

The spelling of 21452500 in words is "twenty-one million, four hundred fifty-two thousand, five hundred".