21035642 has 8 divisors (see below), whose sum is σ = 31662036. Its totient is φ = 10481632.

The previous prime is 21035633. The next prime is 21035687. The reversal of 21035642 is 24653012.

It can be written as a sum of positive squares in 2 ways, for example, as 18309841 + 2725801 = 4279^2 + 1651^2 .

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

It is a super-3 number, since 3×21035642³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

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, 17363 + ... + 18534.

Almost surely, 2^21035642 is an apocalyptic number.

21035642 is a deficient number, since it is larger than the sum of its proper divisors (10626394).

21035642 is a wasteful number, since it uses less digits than its factorization.

21035642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36192.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21035642 is about 4586.4629072958. The cubic root of 21035642 is about 276.0484144573.

Adding to 21035642 its reverse (24653012), we get a palindrome (45688654).

The spelling of 21035642 in words is "twenty-one million, thirty-five thousand, six hundred forty-two".