2778016621 has 2 divisors, whose sum is σ = 2778016622. Its totient is φ = 2778016620.

The previous prime is 2778016607. The next prime is 2778016651. The reversal of 2778016621 is 1266108772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2431870596 + 346146025 = 49314^2 + 18605^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778016621 - 2⁵ = 2778016589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2778016601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389008310 + 1389008311.

It is an arithmetic number, because the mean of its divisors is an integer number (1389008311).

Almost surely, 2^2778016621 is an apocalyptic number.

It is an amenable number.

2778016621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778016621 is an equidigital number, since it uses as much as digits as its factorization.

2778016621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 2778016621 is about 52706.8934865260. The cubic root of 2778016621 is about 1405.7613973167.

The spelling of 2778016621 in words is "two billion, seven hundred seventy-eight million, sixteen thousand, six hundred twenty-one".