2978319781 has 2 divisors, whose sum is σ = 2978319782. Its totient is φ = 2978319780.

The previous prime is 2978319739. The next prime is 2978319791. The reversal of 2978319781 is 1879138792.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2517530625 + 460789156 = 50175^2 + 21466^2 .

It is a cyclic number.

It is not a de Polignac number, because 2978319781 - 2⁷ = 2978319653 is a prime.

It is a super-2 number, since 2×2978319781² = 17740777435791775922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2978319731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1489159890 + 1489159891.

It is an arithmetic number, because the mean of its divisors is an integer number (1489159891).

Almost surely, 2^2978319781 is an apocalyptic number.

It is an amenable number.

2978319781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2978319781 is an equidigital number, since it uses as much as digits as its factorization.

2978319781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 55.

The square root of 2978319781 is about 54573.9844706248. The cubic root of 2978319781 is about 1438.7669133074.

The spelling of 2978319781 in words is "two billion, nine hundred seventy-eight million, three hundred nineteen thousand, seven hundred eighty-one".