21240160 has 24 divisors (see below), whose sum is σ = 50180256. Its totient is φ = 8496000.

The previous prime is 21240133. The next prime is 21240161. The reversal of 21240160 is 6104212.

It is a super-2 number, since 2×21240160² = 902288793651200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66216 + ... + 66535.

It is an arithmetic number, because the mean of its divisors is an integer number (2090844).

Almost surely, 2^21240160 is an apocalyptic number.

21240160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21240160 is an abundant number, since it is smaller than the sum of its proper divisors (28940096).

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

21240160 is a wasteful number, since it uses less digits than its factorization.

21240160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132766 (or 132758 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21240160 is about 4608.7048072099. The cubic root of 21240160 is about 276.9401531097.

Adding to 21240160 its reverse (6104212), we get a palindrome (27344372).

The spelling of 21240160 in words is "twenty-one million, two hundred forty thousand, one hundred sixty".