20309731731 has 12 divisors (see below), whose sum is σ = 30880294120. Its totient is φ = 12827198880.

The previous prime is 20309731721. The next prime is 20309731781. The reversal of 20309731731 is 13713790302.

20309731731 is a `hidden beast` number, since 2 + 0 + 309 + 7 + 317 + 31 = 666.

It is not a de Polignac number, because 20309731731 - 2⁶ = 20309731667 is a prime.

It is a super-2 number, since 2×20309731731² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20309731721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59385010 + ... + 59385351.

Almost surely, 2^20309731731 is an apocalyptic number.

20309731731 is a deficient number, since it is larger than the sum of its proper divisors (10570562389).

20309731731 is a wasteful number, since it uses less digits than its factorization.

20309731731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118770386 (or 118770383 counting only the distinct ones).

The product of its (nonzero) digits is 23814, while the sum is 36.

The spelling of 20309731731 in words is "twenty billion, three hundred nine million, seven hundred thirty-one thousand, seven hundred thirty-one".