20985970 has 16 divisors (see below), whose sum is σ = 38579328. Its totient is φ = 8215600.

The previous prime is 20985961. The next prime is 20985971. The reversal of 20985970 is 7958902.

It is not an unprimeable number, because it can be changed into a prime (20985971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21856 + ... + 22795.

It is an arithmetic number, because the mean of its divisors is an integer number (2411208).

Almost surely, 2^20985970 is an apocalyptic number.

20985970 is a deficient number, since it is larger than the sum of its proper divisors (17593358).

20985970 is a wasteful number, since it uses less digits than its factorization.

20985970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44705.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 20985970 is about 4581.0446406906. The cubic root of 20985970 is about 275.8309631468.

The spelling of 20985970 in words is "twenty million, nine hundred eighty-five thousand, nine hundred seventy".