1645371936 has 144 divisors (see below), whose sum is σ = 5054166936. Its totient is φ = 504741888.

The previous prime is 1645371919. The next prime is 1645371961. The reversal of 1645371936 is 6391735461.

It is a happy number.

1645371936 is a `hidden beast` number, since 1 + 6 + 453 + 7 + 193 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 770395536 + 874976400 = 27756^2 + 29580^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a junction number, because it is equal to n+sod(n) for n = 1645371891 and 1645371900.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2444496 + ... + 2445168.

Almost surely, 2^1645371936 is an apocalyptic number.

1645371936 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645371936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2527083468).

1645371936 is an abundant number, since it is smaller than the sum of its proper divisors (3408795000).

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

1645371936 is a wasteful number, since it uses less digits than its factorization.

1645371936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1355 (or 1344 counting only the distinct ones).

The product of its digits is 408240, while the sum is 45.

The square root of 1645371936 is about 40563.1844903725. The cubic root of 1645371936 is about 1180.5599028214.

The spelling of 1645371936 in words is "one billion, six hundred forty-five million, three hundred seventy-one thousand, nine hundred thirty-six".