21353610 has 32 divisors (see below), whose sum is σ = 51710400. Its totient is φ = 5643008.

The previous prime is 21353603. The next prime is 21353611. The reversal of 21353610 is 1635312.

It is not an unprimeable number, because it can be changed into a prime (21353611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (1615950).

Almost surely, 2^21353610 is an apocalyptic number.

21353610 is an abundant number, since it is smaller than the sum of its proper divisors (30356790).

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

21353610 is a wasteful number, since it uses less digits than its factorization.

21353610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6422.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 21353610 is about 4620.9966457465. The cubic root of 21353610 is about 277.4323510125.

Adding to 21353610 its reverse (1635312), we get a palindrome (22988922).

The spelling of 21353610 in words is "twenty-one million, three hundred fifty-three thousand, six hundred ten".