2778649919 has 2 divisors, whose sum is σ = 2778649920. Its totient is φ = 2778649918.

The previous prime is 2778649897. The next prime is 2778649931. The reversal of 2778649919 is 9199468772.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2778649919 is a prime.

It is a super-2 number, since 2×2778649919² = 15441790744717413122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2778649969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389324959 + 1389324960.

It is an arithmetic number, because the mean of its divisors is an integer number (1389324960).

Almost surely, 2^2778649919 is an apocalyptic number.

2778649919 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778649919 is an equidigital number, since it uses as much as digits as its factorization.

2778649919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13716864, while the sum is 62.

The square root of 2778649919 is about 52712.9008782480. The cubic root of 2778649919 is about 1405.8682119211.

The spelling of 2778649919 in words is "two billion, seven hundred seventy-eight million, six hundred forty-nine thousand, nine hundred nineteen".