20891384 has 32 divisors (see below), whose sum is σ = 40570320. Its totient is φ = 10077696.

The previous prime is 20891333. The next prime is 20891401. The reversal of 20891384 is 48319802.

It is a happy number.

It is a super-3 number, since 3×20891384³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

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, 48032 + ... + 48464.

Almost surely, 2^20891384 is an apocalyptic number.

It is an amenable number.

20891384 is a deficient number, since it is larger than the sum of its proper divisors (19678936).

20891384 is a wasteful number, since it uses less digits than its factorization.

20891384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639 (or 635 counting only the distinct ones).

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

The square root of 20891384 is about 4570.7093541375. The cubic root of 20891384 is about 275.4159391674.

The spelling of 20891384 in words is "twenty million, eight hundred ninety-one thousand, three hundred eighty-four".