1664228977 has 2 divisors, whose sum is σ = 1664228978. Its totient is φ = 1664228976.

The previous prime is 1664228971. The next prime is 1664228987. The reversal of 1664228977 is 7798224661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1657385521 + 6843456 = 40711^2 + 2616^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664228977 - 2⁷ = 1664228849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1664228971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832114488 + 832114489.

It is an arithmetic number, because the mean of its divisors is an integer number (832114489).

Almost surely, 2^1664228977 is an apocalyptic number.

It is an amenable number.

1664228977 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664228977 is an equidigital number, since it uses as much as digits as its factorization.

1664228977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2032128, while the sum is 52.

The square root of 1664228977 is about 40794.9626424636. The cubic root of 1664228977 is about 1185.0527793141.

The spelling of 1664228977 in words is "one billion, six hundred sixty-four million, two hundred twenty-eight thousand, nine hundred seventy-seven".