20405340331 has 8 divisors (see below), whose sum is σ = 20571425280. Its totient is φ = 20239754472.

The previous prime is 20405340299. The next prime is 20405340341. The reversal of 20405340331 is 13304350402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20405340331 - 2⁵ = 20405340299 is a prime.

It is a super-2 number, since 2×20405340331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20405340296 and 20405340305.

It is not an unprimeable number, because it can be changed into a prime (20405340341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42451 + ... + 206428.

It is an arithmetic number, because the mean of its divisors is an integer number (2571428160).

Almost surely, 2^20405340331 is an apocalyptic number.

20405340331 is a deficient number, since it is larger than the sum of its proper divisors (166084949).

20405340331 is a wasteful number, since it uses less digits than its factorization.

20405340331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249545.

The product of its (nonzero) digits is 4320, while the sum is 25.

Adding to 20405340331 its reverse (13304350402), we get a palindrome (33709690733).

The spelling of 20405340331 in words is "twenty billion, four hundred five million, three hundred forty thousand, three hundred thirty-one".