21037340 has 24 divisors (see below), whose sum is σ = 44266992. Its totient is φ = 8398080.

The previous prime is 21037339. The next prime is 21037361. The reversal of 21037340 is 4373012.

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 (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15572 + ... + 16868.

It is an arithmetic number, because the mean of its divisors is an integer number (1844458).

Almost surely, 2^21037340 is an apocalyptic number.

21037340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21037340 is an abundant number, since it is smaller than the sum of its proper divisors (23229652).

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

21037340 is a wasteful number, since it uses less digits than its factorization.

21037340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2117 (or 2115 counting only the distinct ones).

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

The square root of 21037340 is about 4586.6480135280. The cubic root of 21037340 is about 276.0558418131.

The spelling of 21037340 in words is "twenty-one million, thirty-seven thousand, three hundred forty".