1645208385 has 16 divisors (see below), whose sum is σ = 2770877760. Its totient is φ = 831263040.

The previous prime is 1645208329. The next prime is 1645208393. The reversal of 1645208385 is 5838025461.

It is not a de Polignac number, because 1645208385 - 2⁸ = 1645208129 is a prime.

It is a super-3 number, since 3×1645208385³ (a number of 29 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2886046 + ... + 2886615.

It is an arithmetic number, because the mean of its divisors is an integer number (173179860).

Almost surely, 2^1645208385 is an apocalyptic number.

1645208385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645208385 is a deficient number, since it is larger than the sum of its proper divisors (1125669375).

1645208385 is a wasteful number, since it uses less digits than its factorization.

1645208385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5772688.

The product of its (nonzero) digits is 230400, while the sum is 42.

The square root of 1645208385 is about 40561.1684373121. The cubic root of 1645208385 is about 1180.5207853943.

The spelling of 1645208385 in words is "one billion, six hundred forty-five million, two hundred eight thousand, three hundred eighty-five".