21673252 has 6 divisors (see below), whose sum is σ = 37928198. Its totient is φ = 10836624.

The previous prime is 21673241. The next prime is 21673259. The reversal of 21673252 is 25237612.

It can be written as a sum of positive squares in only one way, i.e., 18198756 + 3474496 = 4266^2 + 1864^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21673252.

It is not an unprimeable number, because it can be changed into a prime (21673259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2709153 + ... + 2709160.

Almost surely, 2^21673252 is an apocalyptic number.

It is an amenable number.

21673252 is a deficient number, since it is larger than the sum of its proper divisors (16254946).

21673252 is a wasteful number, since it uses less digits than its factorization.

21673252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5418317 (or 5418315 counting only the distinct ones).

The product of its digits is 5040, while the sum is 28.

The square root of 21673252 is about 4655.4540057872. The cubic root of 21673252 is about 278.8097948635.

The spelling of 21673252 in words is "twenty-one million, six hundred seventy-three thousand, two hundred fifty-two".