1664388877 has 2 divisors, whose sum is σ = 1664388878. Its totient is φ = 1664388876.

The previous prime is 1664388857. The next prime is 1664388899. The reversal of 1664388877 is 7788834661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1649496996 + 14891881 = 40614^2 + 3859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664388877 is a prime.

It is a super-2 number, since 2×1664388877² = 5540380667762642258, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664388857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832194438 + 832194439.

It is an arithmetic number, because the mean of its divisors is an integer number (832194439).

Almost surely, 2^1664388877 is an apocalyptic number.

It is an amenable number.

1664388877 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664388877 is an equidigital number, since it uses as much as digits as its factorization.

1664388877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10838016, while the sum is 58.

The square root of 1664388877 is about 40796.9223961808. The cubic root of 1664388877 is about 1185.0907315978.

The spelling of 1664388877 in words is "one billion, six hundred sixty-four million, three hundred eighty-eight thousand, eight hundred seventy-seven".