20437847513 has 2 divisors, whose sum is σ = 20437847514. Its totient is φ = 20437847512.

The previous prime is 20437847489. The next prime is 20437847581. The reversal of 20437847513 is 31574873402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15633001024 + 4804846489 = 125032^2 + 69317^2 .

It is a cyclic number.

It is not a de Polignac number, because 20437847513 - 2⁸ = 20437847257 is a prime.

It is a super-2 number, since 2×20437847513² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20437847113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10218923756 + 10218923757.

It is an arithmetic number, because the mean of its divisors is an integer number (10218923757).

Almost surely, 2^20437847513 is an apocalyptic number.

It is an amenable number.

20437847513 is a deficient number, since it is larger than the sum of its proper divisors (1).

20437847513 is an equidigital number, since it uses as much as digits as its factorization.

20437847513 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 564480, while the sum is 44.

The spelling of 20437847513 in words is "twenty billion, four hundred thirty-seven million, eight hundred forty-seven thousand, five hundred thirteen".