1645356405 has 128 divisors (see below), whose sum is σ = 3452461056. Its totient is φ = 648806400.

The previous prime is 1645356397. The next prime is 1645356409. The reversal of 1645356405 is 5046535461.

It is not a de Polignac number, because 1645356405 - 2³ = 1645356397 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1645356409) 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 in 127 ways as a sum of consecutive naturals, for example, 6402037 + ... + 6402293.

It is an arithmetic number, because the mean of its divisors is an integer number (26972352).

Almost surely, 2^1645356405 is an apocalyptic number.

1645356405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1645356405 is an abundant number, since it is smaller than the sum of its proper divisors (1807104651).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1645356405 is a wasteful number, since it uses less digits than its factorization.

1645356405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547.

The product of its (nonzero) digits is 216000, while the sum is 39.

The square root of 1645356405 is about 40562.9930478509. The cubic root of 1645356405 is about 1180.5561882948.

The spelling of 1645356405 in words is "one billion, six hundred forty-five million, three hundred fifty-six thousand, four hundred five".