21142185 has 32 divisors (see below), whose sum is σ = 34826880. Its totient is φ = 10948608.

The previous prime is 21142171. The next prime is 21142201. The reversal of 21142185 is 58124112.

It is not a de Polignac number, because 21142185 - 2⁵ = 21142153 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 109449 + ... + 109641.

It is an arithmetic number, because the mean of its divisors is an integer number (1088340).

Almost surely, 2^21142185 is an apocalyptic number.

It is an amenable number.

21142185 is a deficient number, since it is larger than the sum of its proper divisors (13684695).

21142185 is a wasteful number, since it uses less digits than its factorization.

21142185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377.

The product of its digits is 640, while the sum is 24.

The square root of 21142185 is about 4598.0631792093. The cubic root of 21142185 is about 276.5136805206.

Adding to 21142185 its reverse (58124112), we get a palindrome (79266297).

The spelling of 21142185 in words is "twenty-one million, one hundred forty-two thousand, one hundred eighty-five".