21013735 has 8 divisors (see below), whose sum is σ = 25644240. Its totient is φ = 16525824.

The previous prime is 21013723. The next prime is 21013781. The reversal of 21013735 is 53731012.

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

It is a cyclic number.

It is not a de Polignac number, because 21013735 - 2¹⁷ = 20882663 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 35322 + ... + 35911.

It is an arithmetic number, because the mean of its divisors is an integer number (3205530).

Almost surely, 2^21013735 is an apocalyptic number.

21013735 is a deficient number, since it is larger than the sum of its proper divisors (4630505).

21013735 is an equidigital number, since it uses as much as digits as its factorization.

21013735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71297.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21013735 is about 4584.0740613563. The cubic root of 21013735 is about 275.9525534557.

Adding to 21013735 its reverse (53731012), we get a palindrome (74744747).

The spelling of 21013735 in words is "twenty-one million, thirteen thousand, seven hundred thirty-five".