1664001397 has 2 divisors, whose sum is σ = 1664001398. Its totient is φ = 1664001396.

The previous prime is 1664001379. The next prime is 1664001439. The reversal of 1664001397 is 7931004661.

Together with previous prime (1664001379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1416694321 + 247307076 = 37639^2 + 15726^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664001397 - 2¹⁵ = 1663968629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1664001337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832000698 + 832000699.

It is an arithmetic number, because the mean of its divisors is an integer number (832000699).

Almost surely, 2^1664001397 is an apocalyptic number.

It is an amenable number.

1664001397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1664001397 is an equidigital number, since it uses as much as digits as its factorization.

1664001397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 1664001397 is about 40792.1732321287. The cubic root of 1664001397 is about 1184.9987589820.

The spelling of 1664001397 in words is "one billion, six hundred sixty-four million, one thousand, three hundred ninety-seven".