21314240 has 56 divisors (see below), whose sum is σ = 51968400. Its totient is φ = 8322048.

The previous prime is 21314233. The next prime is 21314269. The reversal of 21314240 is 4241312.

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, 12986 + ... + 14534.

Almost surely, 2^21314240 is an apocalyptic number.

21314240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21314240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25984200).

21314240 is an abundant number, since it is smaller than the sum of its proper divisors (30654160).

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

21314240 is a wasteful number, since it uses less digits than its factorization.

21314240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609 (or 1599 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21314240 is about 4616.7347768742. The cubic root of 21314240 is about 277.2617439315.

Adding to 21314240 its reverse (4241312), we get a palindrome (25555552).

The spelling of 21314240 in words is "twenty-one million, three hundred fourteen thousand, two hundred forty".