20984138 has 16 divisors (see below), whose sum is σ = 36430080. Its totient is φ = 8878896.

The previous prime is 20984123. The next prime is 20984141. The reversal of 20984138 is 83148902.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20984098 and 20984107.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8381 + ... + 10592.

It is an arithmetic number, because the mean of its divisors is an integer number (2276880).

Almost surely, 2^20984138 is an apocalyptic number.

20984138 is a deficient number, since it is larger than the sum of its proper divisors (15445942).

20984138 is a wasteful number, since it uses less digits than its factorization.

20984138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19061.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 20984138 is about 4580.8446819337. The cubic root of 20984138 is about 275.8229365616.

The spelling of 20984138 in words is "twenty million, nine hundred eighty-four thousand, one hundred thirty-eight".