20997370 has 16 divisors (see below), whose sum is σ = 37889280. Its totient is φ = 8378064.

The previous prime is 20997349. The next prime is 20997377. The reversal of 20997370 is 7379902.

It is not an unprimeable number, because it can be changed into a prime (20997377) 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, 1999 + ... + 6781.

It is an arithmetic number, because the mean of its divisors is an integer number (2368080).

Almost surely, 2^20997370 is an apocalyptic number.

20997370 is a deficient number, since it is larger than the sum of its proper divisors (16891910).

20997370 is a wasteful number, since it uses less digits than its factorization.

20997370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5229.

The product of its (nonzero) digits is 23814, while the sum is 37.

The square root of 20997370 is about 4582.2887294451. The cubic root of 20997370 is about 275.8808997436.

It can be divided in two parts, 209 and 97370, that added together give a palindrome (97579).

The spelling of 20997370 in words is "twenty million, nine hundred ninety-seven thousand, three hundred seventy".