21350061 has 40 divisors (see below), whose sum is σ = 33759000. Its totient is φ = 13426560.

The previous prime is 21350039. The next prime is 21350071. The reversal of 21350061 is 16005312.

It can be written as a sum of positive squares in 4 ways, for example, as 281961 + 21068100 = 531^2 + 4590^2 .

It is not a de Polignac number, because 21350061 - 2⁵ = 21350029 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21350071) 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 39 ways as a sum of consecutive naturals, for example, 143215 + ... + 143363.

It is an arithmetic number, because the mean of its divisors is an integer number (843975).

Almost surely, 2^21350061 is an apocalyptic number.

It is an amenable number.

21350061 is a deficient number, since it is larger than the sum of its proper divisors (12408939).

21350061 is a wasteful number, since it uses less digits than its factorization.

21350061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 251 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21350061 is about 4620.6126217202. The cubic root of 21350061 is about 277.4169802787.

Adding to 21350061 its reverse (16005312), we get a palindrome (37355373).

The spelling of 21350061 in words is "twenty-one million, three hundred fifty thousand, sixty-one".