21349653 has 16 divisors (see below), whose sum is σ = 31080000. Its totient is φ = 12956544.

The previous prime is 21349621. The next prime is 21349661. The reversal of 21349653 is 35694312.

It is not a de Polignac number, because 21349653 - 2⁵ = 21349621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21349663) 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, 903 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (1942500).

Almost surely, 2^21349653 is an apocalyptic number.

It is an amenable number.

21349653 is a deficient number, since it is larger than the sum of its proper divisors (9730347).

21349653 is a wasteful number, since it uses less digits than its factorization.

21349653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7588.

The product of its digits is 19440, while the sum is 33.

The square root of 21349653 is about 4620.5684715195. The cubic root of 21349653 is about 277.4152131198.

It can be divided in two parts, 2134 and 9653, that multiplied together give a palindrome (20599502).

The spelling of 21349653 in words is "twenty-one million, three hundred forty-nine thousand, six hundred fifty-three".