20731361 has 24 divisors (see below), whose sum is σ = 25116480. Its totient is φ = 17052000.

The previous prime is 20731351. The next prime is 20731391. The reversal of 20731361 is 16313702.

It is a happy number.

It is not a de Polignac number, because 20731361 - 2¹⁴ = 20714977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20731301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 205211 + ... + 205311.

It is an arithmetic number, because the mean of its divisors is an integer number (1046520).

Almost surely, 2^20731361 is an apocalyptic number.

It is an amenable number.

20731361 is a deficient number, since it is larger than the sum of its proper divisors (4385119).

20731361 is a wasteful number, since it uses less digits than its factorization.

20731361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 20731361 is about 4553.1704338845. The cubic root of 20731361 is about 274.7109293030.

The spelling of 20731361 in words is "twenty million, seven hundred thirty-one thousand, three hundred sixty-one".