21042460 has 24 divisors (see below), whose sum is σ = 44341920. Its totient is φ = 8387904.

The previous prime is 21042457. The next prime is 21042467. The reversal of 21042460 is 6424012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21042467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4681 + ... + 7999.

It is an arithmetic number, because the mean of its divisors is an integer number (1847580).

Almost surely, 2^21042460 is an apocalyptic number.

21042460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21042460 is an abundant number, since it is smaller than the sum of its proper divisors (23299460).

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

21042460 is a wasteful number, since it uses less digits than its factorization.

21042460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3645 (or 3643 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21042460 is about 4587.2061213772. The cubic root of 21042460 is about 276.0782351902.

Adding to 21042460 its reverse (6424012), we get a palindrome (27466472).

The spelling of 21042460 in words is "twenty-one million, forty-two thousand, four hundred sixty".