21036342 has 16 divisors (see below), whose sum is σ = 42185520. Its totient is φ = 6993312.

The previous prime is 21036341. The next prime is 21036347. The reversal of 21036342 is 24363012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21036341) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2173 + ... + 6840.

It is an arithmetic number, because the mean of its divisors is an integer number (2636595).

Almost surely, 2^21036342 is an apocalyptic number.

21036342 is an abundant number, since it is smaller than the sum of its proper divisors (21149178).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21036342 is a wasteful number, since it uses less digits than its factorization.

21036342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9407.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 21036342 is about 4586.5392181906. The cubic root of 21036342 is about 276.0514764309.

Adding to 21036342 its reverse (24363012), we get a palindrome (45399354).

The spelling of 21036342 in words is "twenty-one million, thirty-six thousand, three hundred forty-two".