42928871981 has 2 divisors, whose sum is σ = 42928871982. Its totient is φ = 42928871980.

The previous prime is 42928871969. The next prime is 42928872043. The reversal of 42928871981 is 18917882924.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32351777956 + 10577094025 = 179866^2 + 102845^2 .

It is a cyclic number.

It is not a de Polignac number, because 42928871981 - 2⁶ = 42928871917 is a prime.

It is a super-2 number, since 2×42928871981² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42928871981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42928871911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21464435990 + 21464435991.

It is an arithmetic number, because the mean of its divisors is an integer number (21464435991).

Almost surely, 2^42928871981 is an apocalyptic number.

It is an amenable number.

42928871981 is a deficient number, since it is larger than the sum of its proper divisors (1).

42928871981 is an equidigital number, since it uses as much as digits as its factorization.

42928871981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4644864, while the sum is 59.

The spelling of 42928871981 in words is "forty-two billion, nine hundred twenty-eight million, eight hundred seventy-one thousand, nine hundred eighty-one".