21270170 has 16 divisors (see below), whose sum is σ = 39951360. Its totient is φ = 8138064.

The previous prime is 21270167. The next prime is 21270173. The reversal of 21270170 is 7107212.

It is an interprime number because it is at equal distance from previous prime (21270167) and next prime (21270173).

It is not an unprimeable number, because it can be changed into a prime (21270173) 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 7 ways as a sum of consecutive naturals, for example, 46010 + ... + 46469.

It is an arithmetic number, because the mean of its divisors is an integer number (2496960).

Almost surely, 2^21270170 is an apocalyptic number.

21270170 is a deficient number, since it is larger than the sum of its proper divisors (18681190).

21270170 is a wasteful number, since it uses less digits than its factorization.

21270170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92509.

The product of its (nonzero) digits is 196, while the sum is 20.

The square root of 21270170 is about 4611.9594534211. The cubic root of 21270170 is about 277.0705203464.

Adding to 21270170 its reverse (7107212), we get a palindrome (28377382).

The spelling of 21270170 in words is "twenty-one million, two hundred seventy thousand, one hundred seventy".