21242435 has 8 divisors (see below), whose sum is σ = 26990496. Its totient is φ = 15994240.

The previous prime is 21242393. The next prime is 21242443. The reversal of 21242435 is 53424212.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-21242435 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21242435.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124871 + ... + 125040.

It is an arithmetic number, because the mean of its divisors is an integer number (3373812).

Almost surely, 2^21242435 is an apocalyptic number.

21242435 is a deficient number, since it is larger than the sum of its proper divisors (5748061).

21242435 is a wasteful number, since it uses less digits than its factorization.

21242435 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249933.

The product of its digits is 1920, while the sum is 23.

The square root of 21242435 is about 4608.9516161487. The cubic root of 21242435 is about 276.9500402975.

Adding to 21242435 its reverse (53424212), we get a palindrome (74666647).

The spelling of 21242435 in words is "twenty-one million, two hundred forty-two thousand, four hundred thirty-five".