21013170 has 32 divisors (see below), whose sum is σ = 50561280. Its totient is φ = 5589120.

The previous prime is 21013159. The next prime is 21013177. The reversal of 21013170 is 7131012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21013177) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16455 + ... + 17685.

It is an arithmetic number, because the mean of its divisors is an integer number (1580040).

Almost surely, 2^21013170 is an apocalyptic number.

21013170 is an abundant number, since it is smaller than the sum of its proper divisors (29548110).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21013170 is a wasteful number, since it uses less digits than its factorization.

21013170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1810.

The product of its (nonzero) digits is 42, while the sum is 15.

The square root of 21013170 is about 4584.0124345381. The cubic root of 21013170 is about 275.9500802386.

Adding to 21013170 its reverse (7131012), we get a palindrome (28144182).

The spelling of 21013170 in words is "twenty-one million, thirteen thousand, one hundred seventy".