20840517331 has 4 divisors (see below), whose sum is σ = 20841394392. Its totient is φ = 20839640272.

The previous prime is 20840517317. The next prime is 20840517367. The reversal of 20840517331 is 13371504802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20840517331 - 2¹⁵ = 20840484563 is a prime.

It is a super-2 number, since 2×20840517331² (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 (20840512331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401866 + ... + 450751.

It is an arithmetic number, because the mean of its divisors is an integer number (5210348598).

Almost surely, 2^20840517331 is an apocalyptic number.

20840517331 is a deficient number, since it is larger than the sum of its proper divisors (877061).

20840517331 is an equidigital number, since it uses as much as digits as its factorization.

20840517331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 877060.

The product of its (nonzero) digits is 20160, while the sum is 34.

The spelling of 20840517331 in words is "twenty billion, eight hundred forty million, five hundred seventeen thousand, three hundred thirty-one".