21350043 has 48 divisors (see below), whose sum is σ = 37031904. Its totient is φ = 11681280.

The previous prime is 21350039. The next prime is 21350071. The reversal of 21350043 is 34005312.

It is not a de Polignac number, because 21350043 - 2² = 21350039 is a prime.

It is a super-2 number, since 2×21350043² = 911648672203698, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21349998 and 21350025.

It is not an unprimeable number, because it can be changed into a prime (21350083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 68055 + ... + 68367.

It is an arithmetic number, because the mean of its divisors is an integer number (771498).

Almost surely, 2^21350043 is an apocalyptic number.

21350043 is a deficient number, since it is larger than the sum of its proper divisors (15681861).

21350043 is a wasteful number, since it uses less digits than its factorization.

21350043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21350043 is about 4620.6106739261. The cubic root of 21350043 is about 277.4169023163.

Adding to 21350043 its reverse (34005312), we get a palindrome (55355355).

The spelling of 21350043 in words is "twenty-one million, three hundred fifty thousand, forty-three".