21040516 has 12 divisors (see below), whose sum is σ = 42081088. Its totient is φ = 9017352.

The previous prime is 21040511. The next prime is 21040517. The reversal of 21040516 is 61504012.

21040516 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21040493 and 21040502.

It is not an unprimeable number, because it can be changed into a prime (21040511) 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, 375696 + ... + 375751.

Almost surely, 2^21040516 is an apocalyptic number.

It is an amenable number.

21040516 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21040516 is a wasteful number, since it uses less digits than its factorization.

21040516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 751458 (or 751456 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21040516 is about 4586.9942227999. The cubic root of 21040516 is about 276.0697331326.

Adding to 21040516 its reverse (61504012), we get a palindrome (82544528).

The spelling of 21040516 in words is "twenty-one million, forty thousand, five hundred sixteen".