21346985 has 32 divisors (see below), whose sum is σ = 30067200. Its totient is φ = 14426880.

The previous prime is 21346981. The next prime is 21346991. The reversal of 21346985 is 58964312.

It is a happy number.

It is not a de Polignac number, because 21346985 - 2² = 21346981 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21346981) 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 31 ways as a sum of consecutive naturals, for example, 270176 + ... + 270254.

It is an arithmetic number, because the mean of its divisors is an integer number (939600).

Almost surely, 2^21346985 is an apocalyptic number.

It is an amenable number.

21346985 is a deficient number, since it is larger than the sum of its proper divisors (8720215).

21346985 is an equidigital number, since it uses as much as digits as its factorization.

21346985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 112 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 21346985 is about 4620.2797534349. The cubic root of 21346985 is about 277.4036567318.

It can be divided in two parts, 2134 and 6985, that added together give a palindrome (9119).

The spelling of 21346985 in words is "twenty-one million, three hundred forty-six thousand, nine hundred eighty-five".