1645154509 has 2 divisors, whose sum is σ = 1645154510. Its totient is φ = 1645154508.

The previous prime is 1645154449. The next prime is 1645154573. The reversal of 1645154509 is 9054515461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1474329609 + 170824900 = 38397^2 + 13070^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645154509 - 2¹³ = 1645146317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645164509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822577254 + 822577255.

It is an arithmetic number, because the mean of its divisors is an integer number (822577255).

Almost surely, 2^1645154509 is an apocalyptic number.

It is an amenable number.

1645154509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645154509 is an equidigital number, since it uses as much as digits as its factorization.

1645154509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108000, while the sum is 40.

The square root of 1645154509 is about 40560.5042991332. The cubic root of 1645154509 is about 1180.5078989959.

The spelling of 1645154509 in words is "one billion, six hundred forty-five million, one hundred fifty-four thousand, five hundred nine".