21163285 has 16 divisors (see below), whose sum is σ = 29836800. Its totient is φ = 14207040.

The previous prime is 21163253. The next prime is 21163291. The reversal of 21163285 is 58236112.

It is not a de Polignac number, because 21163285 - 2⁵ = 21163253 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14085 + ... + 15514.

It is an arithmetic number, because the mean of its divisors is an integer number (1864800).

Almost surely, 2^21163285 is an apocalyptic number.

It is an amenable number.

21163285 is a deficient number, since it is larger than the sum of its proper divisors (8673515).

21163285 is a wasteful number, since it uses less digits than its factorization.

21163285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29628.

The product of its digits is 2880, while the sum is 28.

The square root of 21163285 is about 4600.3570513603. The cubic root of 21163285 is about 276.6056372539.

Adding to 21163285 its reverse (58236112), we get a palindrome (79399397).

It can be divided in two parts, 21 and 163285, that added together give a triangular number (163306 = T₅₇₁).

The spelling of 21163285 in words is "twenty-one million, one hundred sixty-three thousand, two hundred eighty-five".