1966189457 has 2 divisors, whose sum is σ = 1966189458. Its totient is φ = 1966189456.

The previous prime is 1966189453. The next prime is 1966189469. The reversal of 1966189457 is 7549816691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1741309441 + 224880016 = 41729^2 + 14996^2 .

It is a cyclic number.

It is not a de Polignac number, because 1966189457 - 2² = 1966189453 is a prime.

It is not a weakly prime, because it can be changed into another prime (1966189453) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983094728 + 983094729.

It is an arithmetic number, because the mean of its divisors is an integer number (983094729).

Almost surely, 2^1966189457 is an apocalyptic number.

It is an amenable number.

1966189457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966189457 is an equidigital number, since it uses as much as digits as its factorization.

1966189457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3265920, while the sum is 56.

The square root of 1966189457 is about 44341.7349344836. The cubic root of 1966189457 is about 1252.7808928800.

The spelling of 1966189457 in words is "one billion, nine hundred sixty-six million, one hundred eighty-nine thousand, four hundred fifty-seven".