21103040 has 56 divisors (see below), whose sum is σ = 57436512. Its totient is φ = 7234560.

The previous prime is 21103021. The next prime is 21103051. The reversal of 21103040 is 4030112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2471 + ... + 6950.

It is an arithmetic number, because the mean of its divisors is an integer number (1025652).

Almost surely, 2^21103040 is an apocalyptic number.

21103040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21103040 is an abundant number, since it is smaller than the sum of its proper divisors (36333472).

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

21103040 is an equidigital number, since it uses as much as digits as its factorization.

21103040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9445 (or 9435 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21103040 is about 4593.8045234860. The cubic root of 21103040 is about 276.3429189960.

Adding to 21103040 its reverse (4030112), we get a palindrome (25133152).

The spelling of 21103040 in words is "twenty-one million, one hundred three thousand, forty".