21035424 has 24 divisors (see below), whose sum is σ = 55218240. Its totient is φ = 7011776.

The previous prime is 21035401. The next prime is 21035429. The reversal of 21035424 is 42453012.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21035424.

It is not an unprimeable number, because it can be changed into a prime (21035429) 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, 109464 + ... + 109655.

It is an arithmetic number, because the mean of its divisors is an integer number (2300760).

Almost surely, 2^21035424 is an apocalyptic number.

21035424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21035424 is an abundant number, since it is smaller than the sum of its proper divisors (34182816).

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

21035424 is a wasteful number, since it uses less digits than its factorization.

21035424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219132 (or 219124 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21035424 is about 4586.4391416435. The cubic root of 21035424 is about 276.0474608573.

Adding to 21035424 its reverse (42453012), we get a palindrome (63488436).

The spelling of 21035424 in words is "twenty-one million, thirty-five thousand, four hundred twenty-four".