21174740 has 48 divisors (see below), whose sum is σ = 47349120. Its totient is φ = 7931520.

The previous prime is 21174733. The next prime is 21174749. The reversal of 21174740 is 4747112.

It is a super-2 number, since 2×21174740² = 896739228135200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21174749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38870 + ... + 39410.

It is an arithmetic number, because the mean of its divisors is an integer number (986440).

Almost surely, 2^21174740 is an apocalyptic number.

21174740 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 21174740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23674560).

21174740 is an abundant number, since it is smaller than the sum of its proper divisors (26174380).

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

21174740 is a wasteful number, since it uses less digits than its factorization.

21174740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 21174740 is about 4601.6018949927. The cubic root of 21174740 is about 276.6555341402.

The spelling of 21174740 in words is "twenty-one million, one hundred seventy-four thousand, seven hundred forty".