1691912977 has 2 divisors, whose sum is σ = 1691912978. Its totient is φ = 1691912976.

The previous prime is 1691912921. The next prime is 1691912987. The reversal of 1691912977 is 7792191961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1617970176 + 73942801 = 40224^2 + 8599^2 .

It is a cyclic number.

It is not a de Polignac number, because 1691912977 - 2¹¹ = 1691910929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1691912987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845956488 + 845956489.

It is an arithmetic number, because the mean of its divisors is an integer number (845956489).

Almost surely, 2^1691912977 is an apocalyptic number.

It is an amenable number.

1691912977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691912977 is an equidigital number, since it uses as much as digits as its factorization.

1691912977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 52.

The square root of 1691912977 is about 41132.8697880418. The cubic root of 1691912977 is about 1191.5876877602.

The spelling of 1691912977 in words is "one billion, six hundred ninety-one million, nine hundred twelve thousand, nine hundred seventy-seven".