21461530 has 24 divisors (see below), whose sum is σ = 40393332. Its totient is φ = 8209344.

The previous prime is 21461527. The next prime is 21461533. The reversal of 21461530 is 3516412.

It is an interprime number because it is at equal distance from previous prime (21461527) and next prime (21461533).

It can be written as a sum of positive squares in 2 ways, for example, as 21372129 + 89401 = 4623^2 + 299^2 .

It is not an unprimeable number, because it can be changed into a prime (21461533) 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 11 ways as a sum of consecutive naturals, for example, 3262 + ... + 7318.

Almost surely, 2^21461530 is an apocalyptic number.

21461530 is a deficient number, since it is larger than the sum of its proper divisors (18931802).

21461530 is a wasteful number, since it uses less digits than its factorization.

21461530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4110 (or 4087 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21461530 is about 4632.6590636480. The cubic root of 21461530 is about 277.8989419268.

Adding to 21461530 its reverse (3516412), we get a palindrome (24977942).

The spelling of 21461530 in words is "twenty-one million, four hundred sixty-one thousand, five hundred thirty".