1649744777 has 2 divisors, whose sum is σ = 1649744778. Its totient is φ = 1649744776.

The previous prime is 1649744773. The next prime is 1649744797. The reversal of 1649744777 is 7774479461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1061391241 + 588353536 = 32579^2 + 24256^2 .

It is a cyclic number.

It is not a de Polignac number, because 1649744777 - 2² = 1649744773 is a prime.

It is not a weakly prime, because it can be changed into another prime (1649744771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824872388 + 824872389.

It is an arithmetic number, because the mean of its divisors is an integer number (824872389).

Almost surely, 2^1649744777 is an apocalyptic number.

It is an amenable number.

1649744777 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649744777 is an equidigital number, since it uses as much as digits as its factorization.

1649744777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8297856, while the sum is 56.

The square root of 1649744777 is about 40617.0503237249. The cubic root of 1649744777 is about 1181.6048204010.

The spelling of 1649744777 in words is "one billion, six hundred forty-nine million, seven hundred forty-four thousand, seven hundred seventy-seven".