21325240 has 32 divisors (see below), whose sum is σ = 48114000. Its totient is φ = 8506624.

The previous prime is 21325219. The next prime is 21325279. The reversal of 21325240 is 4252312.

It is a super-2 number, since 2×21325240² = 909531722115200, which contains 22 as substring.

It is a congruent number.

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, 25956 + ... + 26764.

Almost surely, 2^21325240 is an apocalyptic number.

21325240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21325240 is an abundant number, since it is smaller than the sum of its proper divisors (26788760).

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

21325240 is a wasteful number, since it uses less digits than its factorization.

21325240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1479 (or 1475 counting only the distinct ones).

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

The square root of 21325240 is about 4617.9259413724. The cubic root of 21325240 is about 277.3094327796.

Adding to 21325240 its reverse (4252312), we get a palindrome (25577552).

The spelling of 21325240 in words is "twenty-one million, three hundred twenty-five thousand, two hundred forty".