20984397 has 16 divisors (see below), whose sum is σ = 32630400. Its totient is φ = 11990496.

The previous prime is 20984393. The next prime is 20984399. The reversal of 20984397 is 79348902.

It is not a de Polignac number, because 20984397 - 2² = 20984393 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20984393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9168 + ... + 11225.

It is an arithmetic number, because the mean of its divisors is an integer number (2039400).

Almost surely, 2^20984397 is an apocalyptic number.

It is an amenable number.

20984397 is a deficient number, since it is larger than the sum of its proper divisors (11646003).

20984397 is an equidigital number, since it uses as much as digits as its factorization.

20984397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20417 (or 20403 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The square root of 20984397 is about 4580.8729517418. The cubic root of 20984397 is about 275.8240713528.

The spelling of 20984397 in words is "twenty million, nine hundred eighty-four thousand, three hundred ninety-seven".