21040460 has 48 divisors (see below), whose sum is σ = 50912064. Its totient is φ = 7154688.

The previous prime is 21040447. The next prime is 21040463. The reversal of 21040460 is 6404012.

It is a super-3 number, since 3×21040460³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21040463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18632 + ... + 19728.

It is an arithmetic number, because the mean of its divisors is an integer number (1060668).

Almost surely, 2^21040460 is an apocalyptic number.

21040460 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 21040460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25456032).

21040460 is an abundant number, since it is smaller than the sum of its proper divisors (29871604).

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

21040460 is a wasteful number, since it uses less digits than its factorization.

21040460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1250 (or 1248 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21040460 is about 4586.9881185806. The cubic root of 21040460 is about 276.0694882096.

Adding to 21040460 its reverse (6404012), we get a palindrome (27444472).

The spelling of 21040460 in words is "twenty-one million, forty thousand, four hundred sixty".