21021452 has 24 divisors (see below), whose sum is σ = 39365424. Its totient is φ = 9787392.

The previous prime is 21021449. The next prime is 21021457. The reversal of 21021452 is 25412012.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a self number, because there is not a number n which added to its sum of digits gives 21021452.

It is not an unprimeable number, because it can be changed into a prime (21021457) 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, 5003 + ... + 8189.

It is an arithmetic number, because the mean of its divisors is an integer number (1640226).

Almost surely, 2^21021452 is an apocalyptic number.

It is an amenable number.

21021452 is a deficient number, since it is larger than the sum of its proper divisors (18343972).

21021452 is a wasteful number, since it uses less digits than its factorization.

21021452 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3305 (or 3303 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 21021452 is about 4584.9157026057. The cubic root of 21021452 is about 275.9863292256.

Adding to 21021452 its reverse (25412012), we get a palindrome (46433464).

The spelling of 21021452 in words is "twenty-one million, twenty-one thousand, four hundred fifty-two".