21670170 has 32 divisors (see below), whose sum is σ = 52520832. Its totient is φ = 5721792.

The previous prime is 21670141. The next prime is 21670177. The reversal of 21670170 is 7107612.

It is a self number, because there is not a number n which added to its sum of digits gives 21670170.

It is not an unprimeable number, because it can be changed into a prime (21670177) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 417 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (1641276).

Almost surely, 2^21670170 is an apocalyptic number.

21670170 is an abundant number, since it is smaller than the sum of its proper divisors (30850662).

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

21670170 is a wasteful number, since it uses less digits than its factorization.

21670170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7126.

The product of its (nonzero) digits is 588, while the sum is 24.

The square root of 21670170 is about 4655.1229844119. The cubic root of 21670170 is about 278.7965783801.

Adding to 21670170 its reverse (7107612), we get a palindrome (28777782).

The spelling of 21670170 in words is "twenty-one million, six hundred seventy thousand, one hundred seventy".