20400323571 has 12 divisors (see below), whose sum is σ = 29882165040. Its totient is φ = 13408662960.

The previous prime is 20400323569. The next prime is 20400323599. The reversal of 20400323571 is 17532300402.

20400323571 is a `hidden beast` number, since 20 + 40 + 0 + 32 + 3 + 571 = 666.

It is not a de Polignac number, because 20400323571 - 2¹ = 20400323569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20400323371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15962056 + ... + 15963333.

It is an arithmetic number, because the mean of its divisors is an integer number (2490180420).

Almost surely, 2^20400323571 is an apocalyptic number.

20400323571 is a deficient number, since it is larger than the sum of its proper divisors (9481841469).

20400323571 is a wasteful number, since it uses less digits than its factorization.

20400323571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31925466 (or 31925463 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

Adding to 20400323571 its reverse (17532300402), we get a palindrome (37932623973).

The spelling of 20400323571 in words is "twenty billion, four hundred million, three hundred twenty-three thousand, five hundred seventy-one".