20985478 has 8 divisors (see below), whose sum is σ = 31502520. Its totient is φ = 10484640.

The previous prime is 20985467. The next prime is 20985479. The reversal of 20985478 is 87458902.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20985479) 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, 3 + ... + 6478.

It is an arithmetic number, because the mean of its divisors is an integer number (3937815).

Almost surely, 2^20985478 is an apocalyptic number.

20985478 is a deficient number, since it is larger than the sum of its proper divisors (10517042).

20985478 is a wasteful number, since it uses less digits than its factorization.

20985478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8102.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 20985478 is about 4580.9909408337. The cubic root of 20985478 is about 275.8288075813.

The spelling of 20985478 in words is "twenty million, nine hundred eighty-five thousand, four hundred seventy-eight".