21814740 has 72 divisors (see below), whose sum is σ = 70073640. Its totient is φ = 5474304.

The previous prime is 21814739. The next prime is 21814777. The reversal of 21814740 is 4741812.

It can be written as a sum of positive squares in 4 ways, for example, as 5702544 + 16112196 = 2388^2 + 4014^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 505 + ... + 6624.

It is an arithmetic number, because the mean of its divisors is an integer number (973245).

Almost surely, 2^21814740 is an apocalyptic number.

21814740 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 21814740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35036820).

21814740 is an abundant number, since it is smaller than the sum of its proper divisors (48258900).

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

21814740 is a wasteful number, since it uses less digits than its factorization.

21814740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7161 (or 7156 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 21814740 is about 4670.6252258129. The cubic root of 21814740 is about 279.4151909807.

The spelling of 21814740 in words is "twenty-one million, eight hundred fourteen thousand, seven hundred forty".