21032530 has 16 divisors (see below), whose sum is σ = 37929024. Its totient is φ = 8397360.

The previous prime is 21032527. The next prime is 21032533. The reversal of 21032530 is 3523012.

It is an interprime number because it is at equal distance from previous prime (21032527) and next prime (21032533).

It is not an unprimeable number, because it can be changed into a prime (21032533) 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, 4795 + ... + 8065.

It is an arithmetic number, because the mean of its divisors is an integer number (2370564).

Almost surely, 2^21032530 is an apocalyptic number.

21032530 is a deficient number, since it is larger than the sum of its proper divisors (16896494).

21032530 is a wasteful number, since it uses less digits than its factorization.

21032530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3921.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 21032530 is about 4586.1236354900. The cubic root of 21032530 is about 276.0348009748.

Adding to 21032530 its reverse (3523012), we get a palindrome (24555542).

The spelling of 21032530 in words is "twenty-one million, thirty-two thousand, five hundred thirty".