1690661977 has 2 divisors, whose sum is σ = 1690661978. Its totient is φ = 1690661976.

The previous prime is 1690661899. The next prime is 1690661983. The reversal of 1690661977 is 7791660961.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 931714576 + 758947401 = 30524^2 + 27549^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1690661977 is a prime.

It is not a weakly prime, because it can be changed into another prime (1690631977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845330988 + 845330989.

It is an arithmetic number, because the mean of its divisors is an integer number (845330989).

Almost surely, 2^1690661977 is an apocalyptic number.

It is an amenable number.

1690661977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1690661977 is an equidigital number, since it uses as much as digits as its factorization.

1690661977 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 857304, while the sum is 52.

The square root of 1690661977 is about 41117.6601595957. The cubic root of 1690661977 is about 1191.2939288080.

The spelling of 1690661977 in words is "one billion, six hundred ninety million, six hundred sixty-one thousand, nine hundred seventy-seven".