21040452 has 24 divisors (see below), whose sum is σ = 54549600. Its totient is φ = 7013448.

The previous prime is 21040447. The next prime is 21040463. The reversal of 21040452 is 25404012.

21040452 is a `hidden beast` number, since 210 + 4 + 0 + 452 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 97302 + ... + 97517.

It is an arithmetic number, because the mean of its divisors is an integer number (2272900).

Almost surely, 2^21040452 is an apocalyptic number.

It is an amenable number.

21040452 is an abundant number, since it is smaller than the sum of its proper divisors (33509148).

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

21040452 is a wasteful number, since it uses less digits than its factorization.

21040452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194832 (or 194824 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 21040452 is about 4586.9872465487. The cubic root of 21040452 is about 276.0694532206.

Adding to 21040452 its reverse (25404012), we get a palindrome (46444464).

The spelling of 21040452 in words is "twenty-one million, forty thousand, four hundred fifty-two".