1649874857 has 2 divisors, whose sum is σ = 1649874858. Its totient is φ = 1649874856.

The previous prime is 1649874851. The next prime is 1649874923. The reversal of 1649874857 is 7584789461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1219685776 + 430189081 = 34924^2 + 20741^2 .

It is an emirp because it is prime and its reverse (7584789461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1649874857 - 2⁴ = 1649874841 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1649874796 and 1649874805.

It is not a weakly prime, because it can be changed into another prime (1649874851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824937428 + 824937429.

It is an arithmetic number, because the mean of its divisors is an integer number (824937429).

Almost surely, 2^1649874857 is an apocalyptic number.

It is an amenable number.

1649874857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649874857 is an equidigital number, since it uses as much as digits as its factorization.

1649874857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13547520, while the sum is 59.

The square root of 1649874857 is about 40618.6515901254. The cubic root of 1649874857 is about 1181.6358755310.

The spelling of 1649874857 in words is "one billion, six hundred forty-nine million, eight hundred seventy-four thousand, eight hundred fifty-seven".