1645442136 has 144 divisors (see below), whose sum is σ = 4993045200. Its totient is φ = 488726784.

The previous prime is 1645442101. The next prime is 1645442167. The reversal of 1645442136 is 6312445461.

1645442136 is a `hidden beast` number, since 1 + 64 + 544 + 21 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1645442136.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 350541 + ... + 355203.

It is an arithmetic number, because the mean of its divisors is an integer number (34673925).

Almost surely, 2^1645442136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645442136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2496522600).

1645442136 is an abundant number, since it is smaller than the sum of its proper divisors (3347603064).

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

1645442136 is a wasteful number, since it uses less digits than its factorization.

1645442136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4730 (or 4710 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 1645442136 is about 40564.0497978197. The cubic root of 1645442136 is about 1180.5766921614.

Adding to 1645442136 its reverse (6312445461), we get a palindrome (7957887597).

The spelling of 1645442136 in words is "one billion, six hundred forty-five million, four hundred forty-two thousand, one hundred thirty-six".