1691806049 has 2 divisors, whose sum is σ = 1691806050. Its totient is φ = 1691806048.

The previous prime is 1691806033. The next prime is 1691806069. The reversal of 1691806049 is 9406081961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1588580449 + 103225600 = 39857^2 + 10160^2 .

It is a cyclic number.

It is not a de Polignac number, because 1691806049 - 2⁴ = 1691806033 is a prime.

It is not a weakly prime, because it can be changed into another prime (1691806069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845903024 + 845903025.

It is an arithmetic number, because the mean of its divisors is an integer number (845903025).

Almost surely, 2^1691806049 is an apocalyptic number.

It is an amenable number.

1691806049 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691806049 is an equidigital number, since it uses as much as digits as its factorization.

1691806049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 1691806049 is about 41131.5699797613. The cubic root of 1691806049 is about 1191.5625846621.

The spelling of 1691806049 in words is "one billion, six hundred ninety-one million, eight hundred six thousand, forty-nine".