21374144 has 56 divisors (see below), whose sum is σ = 46896528. Its totient is φ = 9584640.

The previous prime is 21374113. The next prime is 21374147. The reversal of 21374144 is 44147312.

It is a super-3 number, since 3×21374144³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21374147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68132 + ... + 68444.

It is an arithmetic number, because the mean of its divisors is an integer number (837438).

Almost surely, 2^21374144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21374144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23448264).

21374144 is an abundant number, since it is smaller than the sum of its proper divisors (25522384).

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

21374144 is a wasteful number, since it uses less digits than its factorization.

21374144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 423 counting only the distinct ones).

The product of its digits is 2688, while the sum is 26.

The square root of 21374144 is about 4623.2179269422. The cubic root of 21374144 is about 277.5212504355.

The spelling of 21374144 in words is "twenty-one million, three hundred seventy-four thousand, one hundred forty-four".