312779181989 has 2 divisors, whose sum is σ = 312779181990. Its totient is φ = 312779181988.

The previous prime is 312779181887. The next prime is 312779182007. The reversal of 312779181989 is 989181977213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 312425102500 + 354079489 = 558950^2 + 18817^2 .

It is a cyclic number.

It is not a de Polignac number, because 312779181989 - 2⁸ = 312779181733 is a prime.

It is a super-2 number, since 2×312779181989² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (312779181089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156389590994 + 156389590995.

It is an arithmetic number, because the mean of its divisors is an integer number (156389590995).

Almost surely, 2^312779181989 is an apocalyptic number.

It is an amenable number.

312779181989 is a deficient number, since it is larger than the sum of its proper divisors (1).

312779181989 is an equidigital number, since it uses as much as digits as its factorization.

312779181989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13716864, while the sum is 65.

The spelling of 312779181989 in words is "three hundred twelve billion, seven hundred seventy-nine million, one hundred eighty-one thousand, nine hundred eighty-nine".