43911478781 has 2 divisors, whose sum is σ = 43911478782. Its totient is φ = 43911478780.

The previous prime is 43911478747. The next prime is 43911478789. The reversal of 43911478781 is 18787411934.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37665105625 + 6246373156 = 194075^2 + 79034^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43911478781 is a prime.

It is a super-2 number, since 2×43911478781² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43911478789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21955739390 + 21955739391.

It is an arithmetic number, because the mean of its divisors is an integer number (21955739391).

Almost surely, 2^43911478781 is an apocalyptic number.

It is an amenable number.

43911478781 is a deficient number, since it is larger than the sum of its proper divisors (1).

43911478781 is an equidigital number, since it uses as much as digits as its factorization.

43911478781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 53.

The spelling of 43911478781 in words is "forty-three billion, nine hundred eleven million, four hundred seventy-eight thousand, seven hundred eighty-one".