1645704065 has 8 divisors (see below), whose sum is σ = 1975689960. Its totient is φ = 1315999872.

The previous prime is 1645704059. The next prime is 1645704079. The reversal of 1645704065 is 5604075461.

It can be written as a sum of positive squares in 4 ways, for example, as 72471169 + 1573232896 = 8513^2 + 39664^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1645704065 - 2⁸ = 1645703809 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57350 + ... + 81119.

It is an arithmetic number, because the mean of its divisors is an integer number (246961245).

Almost surely, 2^1645704065 is an apocalyptic number.

It is an amenable number.

1645704065 is a deficient number, since it is larger than the sum of its proper divisors (329985895).

1645704065 is a wasteful number, since it uses less digits than its factorization.

1645704065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140851.

The product of its (nonzero) digits is 100800, while the sum is 38.

The square root of 1645704065 is about 40567.2782547708. The cubic root of 1645704065 is about 1180.6393320358.

The spelling of 1645704065 in words is "one billion, six hundred forty-five million, seven hundred four thousand, sixty-five".