20031511493 has 6 divisors (see below), whose sum is σ = 23301962406. Its totient is φ = 17169866952.

The previous prime is 20031511483. The next prime is 20031511517. The reversal of 20031511493 is 39411513002.

It can be written as a sum of positive squares in only one way, i.e., 12358101889 + 7673409604 = 111167^2 + 87598^2 .

It is not a de Polignac number, because 20031511493 - 2⁴ = 20031511477 is a prime.

It is a super-2 number, since 2×20031511493² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20031511483) 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 5 ways as a sum of consecutive naturals, for example, 204403130 + ... + 204403227.

It is an arithmetic number, because the mean of its divisors is an integer number (3883660401).

Almost surely, 2^20031511493 is an apocalyptic number.

It is an amenable number.

20031511493 is a deficient number, since it is larger than the sum of its proper divisors (3270450913).

20031511493 is an equidigital number, since it uses as much as digits as its factorization.

20031511493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408806371 (or 408806364 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 29.

The spelling of 20031511493 in words is "twenty billion, thirty-one million, five hundred eleven thousand, four hundred ninety-three".