20781368 has 16 divisors (see below), whose sum is σ = 39017160. Its totient is φ = 10376800.

The previous prime is 20781367. The next prime is 20781389. The reversal of 20781368 is 86318702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20781367) 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, 7538 + ... + 9918.

Almost surely, 2^20781368 is an apocalyptic number.

It is an amenable number.

20781368 is a deficient number, since it is larger than the sum of its proper divisors (18235792).

20781368 is a wasteful number, since it uses less digits than its factorization.

20781368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3478 (or 3474 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 20781368 is about 4558.6585746248. The cubic root of 20781368 is about 274.9316325914.

The spelling of 20781368 in words is "twenty million, seven hundred eighty-one thousand, three hundred sixty-eight".