20731768 has 8 divisors (see below), whose sum is σ = 38872080. Its totient is φ = 10365880.

The previous prime is 20731759. The next prime is 20731769. The reversal of 20731768 is 86713702.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1295728 + ... + 1295743.

It is an arithmetic number, because the mean of its divisors is an integer number (4859010).

Almost surely, 2^20731768 is an apocalyptic number.

It is an amenable number.

20731768 is a deficient number, since it is larger than the sum of its proper divisors (18140312).

20731768 is a wasteful number, since it uses less digits than its factorization.

20731768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591477 (or 2591473 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 20731768 is about 4553.2151277971. The cubic root of 20731768 is about 274.7127270080.

The spelling of 20731768 in words is "twenty million, seven hundred thirty-one thousand, seven hundred sixty-eight".