20113731 has 16 divisors (see below), whose sum is σ = 32507520. Its totient is φ = 12189960.

The previous prime is 20113721. The next prime is 20113747. The reversal of 20113731 is 13731102.

It is a de Polignac number, because none of the positive numbers 2^k-20113731 is a prime.

It is a super-2 number, since 2×20113731² = 809124349480722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20113721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33565 + ... + 34158.

It is an arithmetic number, because the mean of its divisors is an integer number (2031720).

Almost surely, 2^20113731 is an apocalyptic number.

20113731 is a deficient number, since it is larger than the sum of its proper divisors (12393789).

20113731 is a wasteful number, since it uses less digits than its factorization.

20113731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67743 (or 67737 counting only the distinct ones).

The product of its (nonzero) digits is 126, while the sum is 18.

The square root of 20113731 is about 4484.8334417233. The cubic root of 20113731 is about 271.9553118265.

Adding to 20113731 its reverse (13731102), we get a palindrome (33844833).

The spelling of 20113731 in words is "twenty million, one hundred thirteen thousand, seven hundred thirty-one".