21170853 has 12 divisors (see below), whose sum is σ = 33360288. Its totient is φ = 12830760.

The previous prime is 21170789. The next prime is 21170857. The reversal of 21170853 is 35807112.

It is not a de Polignac number, because 21170853 - 2⁶ = 21170789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170857) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106825 + ... + 107022.

It is an arithmetic number, because the mean of its divisors is an integer number (2780024).

Almost surely, 2^21170853 is an apocalyptic number.

It is an amenable number.

21170853 is a deficient number, since it is larger than the sum of its proper divisors (12189435).

21170853 is a wasteful number, since it uses less digits than its factorization.

21170853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213864 (or 213861 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 21170853 is about 4601.1795226876. The cubic root of 21170853 is about 276.6386047569.

Adding to 21170853 its reverse (35807112), we get a palindrome (56977965).

The spelling of 21170853 in words is "twenty-one million, one hundred seventy thousand, eight hundred fifty-three".