21041000 has 64 divisors (see below), whose sum is σ = 50291280. Its totient is φ = 8236800.

The previous prime is 21040997. The next prime is 21041011. The reversal of 21041000 is 14012.

It can be written as a sum of positive squares in 8 ways, for example, as 2910436 + 18130564 = 1706^2 + 4258^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52802 + ... + 53198.

Almost surely, 2^21041000 is an apocalyptic number.

21041000 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 21041000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25145640).

21041000 is an abundant number, since it is smaller than the sum of its proper divisors (29250280).

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

21041000 is a wasteful number, since it uses less digits than its factorization.

21041000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 471 (or 457 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21041000 is about 4587.0469803568. The cubic root of 21041000 is about 276.0718499490.

Adding to 21041000 its reverse (14012), we get a palindrome (21055012).

The spelling of 21041000 in words is "twenty-one million, forty-one thousand".