21242835 has 12 divisors (see below), whose sum is σ = 36820992. Its totient is φ = 11329488.

The previous prime is 21242833. The next prime is 21242839. The reversal of 21242835 is 53824212.

It is not a de Polignac number, because 21242835 - 2¹ = 21242833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21242799 and 21242808.

It is not an unprimeable number, because it can be changed into a prime (21242833) 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 11 ways as a sum of consecutive naturals, for example, 235987 + ... + 236076.

It is an arithmetic number, because the mean of its divisors is an integer number (3068416).

Almost surely, 2^21242835 is an apocalyptic number.

21242835 is a deficient number, since it is larger than the sum of its proper divisors (15578157).

21242835 is a wasteful number, since it uses less digits than its factorization.

21242835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472074 (or 472071 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21242835 is about 4608.9950097608. The cubic root of 21242835 is about 276.9517786312.

The spelling of 21242835 in words is "twenty-one million, two hundred forty-two thousand, eight hundred thirty-five".