43213278781 has 2 divisors, whose sum is σ = 43213278782. Its totient is φ = 43213278780.

The previous prime is 43213278763. The next prime is 43213278863. The reversal of 43213278781 is 18787231234.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42259024900 + 954253881 = 205570^2 + 30891^2 .

It is a cyclic number.

It is not a de Polignac number, because 43213278781 - 2¹³ = 43213270589 is a prime.

It is a super-2 number, since 2×43213278781² (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 (43213278701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21606639390 + 21606639391.

It is an arithmetic number, because the mean of its divisors is an integer number (21606639391).

Almost surely, 2^43213278781 is an apocalyptic number.

It is an amenable number.

43213278781 is a deficient number, since it is larger than the sum of its proper divisors (1).

43213278781 is an equidigital number, since it uses as much as digits as its factorization.

43213278781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 46.

The spelling of 43213278781 in words is "forty-three billion, two hundred thirteen million, two hundred seventy-eight thousand, seven hundred eighty-one".