21006035 has 4 divisors (see below), whose sum is σ = 25207248. Its totient is φ = 16804824.

The previous prime is 21006019. The next prime is 21006053. The reversal of 21006035 is 53060012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21006035 - 2⁴ = 21006019 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2100599 + ... + 2100608.

It is an arithmetic number, because the mean of its divisors is an integer number (6301812).

Almost surely, 2^21006035 is an apocalyptic number.

21006035 is a deficient number, since it is larger than the sum of its proper divisors (4201213).

21006035 is an equidigital number, since it uses as much as digits as its factorization.

21006035 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4201212.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21006035 is about 4583.2341201383. The cubic root of 21006035 is about 275.9188438487.

Adding to 21006035 its reverse (53060012), we get a palindrome (74066047).

The spelling of 21006035 in words is "twenty-one million, six thousand, thirty-five".