21342520 has 32 divisors (see below), whose sum is σ = 48399120. Its totient is φ = 8469760.

The previous prime is 21342511. The next prime is 21342523. The reversal of 21342520 is 2524312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21342523) 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 7 ways as a sum of consecutive naturals, for example, 3204 + ... + 7276.

Almost surely, 2^21342520 is an apocalyptic number.

21342520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21342520 is an abundant number, since it is smaller than the sum of its proper divisors (27056600).

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

21342520 is a wasteful number, since it uses less digits than its factorization.

21342520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4215 (or 4211 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21342520 is about 4619.7965323161. The cubic root of 21342520 is about 277.3843145203.

Adding to 21342520 its reverse (2524312), we get a palindrome (23866832).

The spelling of 21342520 in words is "twenty-one million, three hundred forty-two thousand, five hundred twenty".