20731408 has 40 divisors (see below), whose sum is σ = 41434848. Its totient is φ = 10044672.

The previous prime is 20731397. The next prime is 20731409. The reversal of 20731408 is 80413702.

It is not an unprimeable number, because it can be changed into a prime (20731409) 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, 88860 + ... + 89092.

Almost surely, 2^20731408 is an apocalyptic number.

It is an amenable number.

20731408 is a deficient number, since it is larger than the sum of its proper divisors (20703440).

20731408 is a wasteful number, since it uses less digits than its factorization.

20731408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 20731408 is about 4553.1755951204. The cubic root of 20731408 is about 274.7111369016.

It can be divided in two parts, 2073 and 1408, that added together give a square (3481 = 59²).

The spelling of 20731408 in words is "twenty million, seven hundred thirty-one thousand, four hundred eight".