20731388 has 12 divisors (see below), whose sum is σ = 36545712. Its totient is φ = 10289760.

The previous prime is 20731351. The next prime is 20731391. The reversal of 20731388 is 88313702.

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, 18368 + ... + 19463.

It is an arithmetic number, because the mean of its divisors is an integer number (3045476).

Almost surely, 2^20731388 is an apocalyptic number.

It is an amenable number.

20731388 is a deficient number, since it is larger than the sum of its proper divisors (15814324).

20731388 is a wasteful number, since it uses less digits than its factorization.

20731388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37972 (or 37970 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 20731388 is about 4553.1733988505. The cubic root of 20731388 is about 274.7110485618.

The spelling of 20731388 in words is "twenty million, seven hundred thirty-one thousand, three hundred eighty-eight".