2778353821 has 2 divisors, whose sum is σ = 2778353822. Its totient is φ = 2778353820.

The previous prime is 2778353803. The next prime is 2778353833. The reversal of 2778353821 is 1283538772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2321890596 + 456463225 = 48186^2 + 21365^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778353821 - 2⁷ = 2778353693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2778353881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389176910 + 1389176911.

It is an arithmetic number, because the mean of its divisors is an integer number (1389176911).

Almost surely, 2^2778353821 is an apocalyptic number.

It is an amenable number.

2778353821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778353821 is an equidigital number, since it uses as much as digits as its factorization.

2778353821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 564480, while the sum is 46.

The square root of 2778353821 is about 52710.0922120233. The cubic root of 2778353821 is about 1405.8182728541.

The spelling of 2778353821 in words is "two billion, seven hundred seventy-eight million, three hundred fifty-three thousand, eight hundred twenty-one".