21453610 has 8 divisors (see below), whose sum is σ = 38616516. Its totient is φ = 8581440.

The previous prime is 21453583. The next prime is 21453611. The reversal of 21453610 is 1635412.

It can be written as a sum of positive squares in 2 ways, for example, as 17497489 + 3956121 = 4183^2 + 1989^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21453611) 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 3 ways as a sum of consecutive naturals, for example, 1072671 + ... + 1072690.

Almost surely, 2^21453610 is an apocalyptic number.

21453610 is a deficient number, since it is larger than the sum of its proper divisors (17162906).

21453610 is a wasteful number, since it uses less digits than its factorization.

21453610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145368.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21453610 is about 4631.8041841166. The cubic root of 21453610 is about 277.8647531494.

It can be divided in two parts, 214 and 53610, that added together give a square (53824 = 232²).

The spelling of 21453610 in words is "twenty-one million, four hundred fifty-three thousand, six hundred ten".