20947170 has 16 divisors (see below), whose sum is σ = 50273280. Its totient is φ = 5585904.

The previous prime is 20947169. The next prime is 20947189. The reversal of 20947170 is 7174902.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 698239 = 20947170 / (2 + 0 + 9 + 4 + 7 + 1 + 7 + 0).

It is a plaindrome in base 13.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 349090 + ... + 349149.

It is an arithmetic number, because the mean of its divisors is an integer number (3142080).

Almost surely, 2^20947170 is an apocalyptic number.

20947170 is an abundant number, since it is smaller than the sum of its proper divisors (29326110).

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

20947170 is a wasteful number, since it uses less digits than its factorization.

20947170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698249.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 20947170 is about 4576.8078395318. The cubic root of 20947170 is about 275.6608678596.

The spelling of 20947170 in words is "twenty million, nine hundred forty-seven thousand, one hundred seventy".