20898391 has 8 divisors (see below), whose sum is σ = 21269664. Its totient is φ = 20530560.

The previous prime is 20898379. The next prime is 20898401. The reversal of 20898391 is 19389802.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20898391 - 2⁷ = 20898263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20898091) 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, 13371 + ... + 14851.

It is an arithmetic number, because the mean of its divisors is an integer number (2658708).

Almost surely, 2^20898391 is an apocalyptic number.

20898391 is a deficient number, since it is larger than the sum of its proper divisors (371273).

20898391 is a wasteful number, since it uses less digits than its factorization.

20898391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 20898391 is about 4571.4758010953. The cubic root of 20898391 is about 275.4467273585.

The spelling of 20898391 in words is "twenty million, eight hundred ninety-eight thousand, three hundred ninety-one".