43278931691 has 2 divisors, whose sum is σ = 43278931692. Its totient is φ = 43278931690.

The previous prime is 43278931681. The next prime is 43278931699. The reversal of 43278931691 is 19613987234.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 43278931691 - 2⁶ = 43278931627 is a prime.

It is not a weakly prime, because it can be changed into another prime (43278931699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21639465845 + 21639465846.

It is an arithmetic number, because the mean of its divisors is an integer number (21639465846).

Almost surely, 2^43278931691 is an apocalyptic number.

43278931691 is a deficient number, since it is larger than the sum of its proper divisors (1).

43278931691 is an equidigital number, since it uses as much as digits as its factorization.

43278931691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 53.

The spelling of 43278931691 in words is "forty-three billion, two hundred seventy-eight million, nine hundred thirty-one thousand, six hundred ninety-one".