20731384 has 16 divisors (see below), whose sum is σ = 38922120. Its totient is φ = 10352160.

The previous prime is 20731351. The next prime is 20731391. The reversal of 20731384 is 48313702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8262 + ... + 10474.

Almost surely, 2^20731384 is an apocalyptic number.

It is an amenable number.

20731384 is a deficient number, since it is larger than the sum of its proper divisors (18190736).

20731384 is a wasteful number, since it uses less digits than its factorization.

20731384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3390 (or 3386 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20731384 is about 4553.1729595964. The cubic root of 20731384 is about 274.7110308938.

It can be divided in two parts, 20731 and 384, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 20731384 in words is "twenty million, seven hundred thirty-one thousand, three hundred eighty-four".