21450243 has 8 divisors (see below), whose sum is σ = 30282768. Its totient is φ = 13458944.

The previous prime is 21450241. The next prime is 21450293. The reversal of 21450243 is 34205412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21450243 - 2¹ = 21450241 is a prime.

It is a super-2 number, since 2×21450243² = 920225849518098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21450241) 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 in 7 ways as a sum of consecutive naturals, for example, 210246 + ... + 210347.

It is an arithmetic number, because the mean of its divisors is an integer number (3785346).

Almost surely, 2^21450243 is an apocalyptic number.

21450243 is a deficient number, since it is larger than the sum of its proper divisors (8832525).

21450243 is a wasteful number, since it uses less digits than its factorization.

21450243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420613.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 21450243 is about 4631.4407045756. The cubic root of 21450243 is about 277.8502160532.

Adding to 21450243 its reverse (34205412), we get a palindrome (55655655).

The spelling of 21450243 in words is "twenty-one million, four hundred fifty thousand, two hundred forty-three".