21652170 has 16 divisors (see below), whose sum is σ = 51965280. Its totient is φ = 5773904.

The previous prime is 21652159. The next prime is 21652171. The reversal of 21652170 is 7125612.

It is a zygodrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 21652170.

It is not an unprimeable number, because it can be changed into a prime (21652171) 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, 360840 + ... + 360899.

It is an arithmetic number, because the mean of its divisors is an integer number (3247830).

Almost surely, 2^21652170 is an apocalyptic number.

21652170 is an abundant number, since it is smaller than the sum of its proper divisors (30313110).

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

21652170 is a wasteful number, since it uses less digits than its factorization.

21652170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721749.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21652170 is about 4653.1892289053. The cubic root of 21652170 is about 278.7193642724.

Adding to 21652170 its reverse (7125612), we get a palindrome (28777782).

The spelling of 21652170 in words is "twenty-one million, six hundred fifty-two thousand, one hundred seventy".