21074040 has 256 divisors, whose sum is σ = 80640000. Its totient is φ = 4852224.

The previous prime is 21074023. The next prime is 21074051. The reversal of 21074040 is 4047012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 266721 + ... + 266799.

It is an arithmetic number, because the mean of its divisors is an integer number (315000).

Almost surely, 2^21074040 is an apocalyptic number.

21074040 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 21074040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40320000).

21074040 is an abundant number, since it is smaller than the sum of its proper divisors (59565960).

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

21074040 is a wasteful number, since it uses less digits than its factorization.

21074040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 21074040 is about 4590.6470132216. The cubic root of 21074040 is about 276.2162766038.

The spelling of 21074040 in words is "twenty-one million, seventy-four thousand, forty".