21461586 has 16 divisors (see below), whose sum is σ = 43198464. Its totient is φ = 7107984.

The previous prime is 21461581. The next prime is 21461593. The reversal of 21461586 is 68516412.

It is not an unprimeable number, because it can be changed into a prime (21461581) 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 7 ways as a sum of consecutive naturals, for example, 10450 + ... + 12333.

It is an arithmetic number, because the mean of its divisors is an integer number (2699904).

Almost surely, 2^21461586 is an apocalyptic number.

21461586 is an abundant number, since it is smaller than the sum of its proper divisors (21736878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21461586 is a wasteful number, since it uses less digits than its factorization.

21461586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22945.

The product of its digits is 11520, while the sum is 33.

The square root of 21461586 is about 4632.6651076891. The cubic root of 21461586 is about 277.8991836357.

Adding to 21461586 its reverse (68516412), we get a palindrome (89977998).

The spelling of 21461586 in words is "twenty-one million, four hundred sixty-one thousand, five hundred eighty-six".