1645378297 has 2 divisors, whose sum is σ = 1645378298. Its totient is φ = 1645378296.

The previous prime is 1645378291. The next prime is 1645378349. The reversal of 1645378297 is 7928735461.

It is an a-pointer prime, because the next prime (1645378349) can be obtained adding 1645378297 to its sum of digits (52).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1553621056 + 91757241 = 39416^2 + 9579^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645378297 - 2¹⁵ = 1645345529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1645378291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822689148 + 822689149.

It is an arithmetic number, because the mean of its divisors is an integer number (822689149).

Almost surely, 2^1645378297 is an apocalyptic number.

It is an amenable number.

1645378297 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645378297 is an equidigital number, since it uses as much as digits as its factorization.

1645378297 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2540160, while the sum is 52.

The square root of 1645378297 is about 40563.2628988350. The cubic root of 1645378297 is about 1180.5614241658.

The spelling of 1645378297 in words is "one billion, six hundred forty-five million, three hundred seventy-eight thousand, two hundred ninety-seven".