21337040 has 80 divisors (see below), whose sum is σ = 54438480. Its totient is φ = 7741440.

The previous prime is 21337037. The next prime is 21337061. The reversal of 21337040 is 4073312.

21337040 = T₁₁ + T₁₂ + ... + T₅₀₃.

It can be written as a sum of positive squares in 8 ways, for example, as 29584 + 21307456 = 172^2 + 4616^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

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, 39170 + ... + 39710.

It is an arithmetic number, because the mean of its divisors is an integer number (680481).

Almost surely, 2^21337040 is an apocalyptic number.

21337040 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 21337040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27219240).

21337040 is an abundant number, since it is smaller than the sum of its proper divisors (33101440).

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

21337040 is a wasteful number, since it uses less digits than its factorization.

21337040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600 (or 594 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 21337040 is about 4619.2033945259. The cubic root of 21337040 is about 277.3605716796.

The spelling of 21337040 in words is "twenty-one million, three hundred thirty-seven thousand, forty".