21461385 has 16 divisors (see below), whose sum is σ = 37460160. Its totient is φ = 10405440.

The previous prime is 21461359. The next prime is 21461399. The reversal of 21461385 is 58316412.

It is not a de Polignac number, because 21461385 - 2¹¹ = 21459337 is a prime.

It is a super-2 number, since 2×21461385² = 921182092236450, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 64870 + ... + 65199.

It is an arithmetic number, because the mean of its divisors is an integer number (2341260).

Almost surely, 2^21461385 is an apocalyptic number.

It is an amenable number.

21461385 is a deficient number, since it is larger than the sum of its proper divisors (15998775).

21461385 is a wasteful number, since it uses less digits than its factorization.

21461385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130088.

The product of its digits is 5760, while the sum is 30.

The square root of 21461385 is about 4632.6434138621. The cubic root of 21461385 is about 277.8983160715.

Adding to 21461385 its reverse (58316412), we get a palindrome (79777797).

The spelling of 21461385 in words is "twenty-one million, four hundred sixty-one thousand, three hundred eighty-five".