21241040 has 20 divisors (see below), whose sum is σ = 49385604. Its totient is φ = 8496384.

The previous prime is 21241037. The next prime is 21241043. The reversal of 21241040 is 4014212.

It is an interprime number because it is at equal distance from previous prime (21241037) and next prime (21241043).

It can be written as a sum of positive squares in 2 ways, for example, as 13601344 + 7639696 = 3688^2 + 2764^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21241043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132677 + ... + 132836.

Almost surely, 2^21241040 is an apocalyptic number.

21241040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21241040 is an abundant number, since it is smaller than the sum of its proper divisors (28144564).

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

21241040 is a wasteful number, since it uses less digits than its factorization.

21241040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265526 (or 265520 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 21241040 is about 4608.8002777296. The cubic root of 21241040 is about 276.9439776881.

Adding to 21241040 its reverse (4014212), we get a palindrome (25255252).

The spelling of 21241040 in words is "twenty-one million, two hundred forty-one thousand, forty".