20984291 has 4 divisors (see below), whose sum is σ = 21551472. Its totient is φ = 20417112.

The previous prime is 20984287. The next prime is 20984321. The reversal of 20984291 is 19248902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19248902 = 2 ⋅9624451.

It is a cyclic number.

It is not a de Polignac number, because 20984291 - 2² = 20984287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20984221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283535 + ... + 283608.

It is an arithmetic number, because the mean of its divisors is an integer number (5387868).

Almost surely, 2^20984291 is an apocalyptic number.

20984291 is a deficient number, since it is larger than the sum of its proper divisors (567181).

20984291 is an equidigital number, since it uses as much as digits as its factorization.

20984291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567180.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 20984291 is about 4580.8613818800. The cubic root of 20984291 is about 275.8236069220.

The spelling of 20984291 in words is "twenty million, nine hundred eighty-four thousand, two hundred ninety-one".