21500452 has 6 divisors (see below), whose sum is σ = 37625798. Its totient is φ = 10750224.

The previous prime is 21500449. The next prime is 21500459. The reversal of 21500452 is 25400512.

It can be written as a sum of positive squares in only one way, i.e., 19501056 + 1999396 = 4416^2 + 1414^2 .

It is not an unprimeable number, because it can be changed into a prime (21500459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2687553 + ... + 2687560.

Almost surely, 2^21500452 is an apocalyptic number.

It is an amenable number.

21500452 is a deficient number, since it is larger than the sum of its proper divisors (16125346).

21500452 is a wasteful number, since it uses less digits than its factorization.

21500452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5375117 (or 5375115 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 21500452 is about 4636.8579879052. The cubic root of 21500452 is about 278.0668369222.

Adding to 21500452 its reverse (25400512), we get a palindrome (46900964).

It can be divided in two parts, 21500 and 452, that added together give a cube (21952 = 28³).

The spelling of 21500452 in words is "twenty-one million, five hundred thousand, four hundred fifty-two".