64381945 has 24 divisors (see below), whose sum is σ = 81901512. Its totient is φ = 48576000.

The previous prime is 64381939. The next prime is 64381949. The reversal of 64381945 is 54918346.

It can be written as a sum of positive squares in 4 ways, for example, as 29713401 + 34668544 = 5451^2 + 5888^2 .

It is not a de Polignac number, because 64381945 - 2⁵ = 64381913 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64381898 and 64381907.

It is not an unprimeable number, because it can be changed into a prime (64381949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 267025 + ... + 267265.

It is an arithmetic number, because the mean of its divisors is an integer number (3412563).

Almost surely, 2^64381945 is an apocalyptic number.

It is an amenable number.

64381945 is a deficient number, since it is larger than the sum of its proper divisors (17519567).

64381945 is a wasteful number, since it uses less digits than its factorization.

64381945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393 (or 370 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The square root of 64381945 is about 8023.8360526621. The cubic root of 64381945 is about 400.7941410566.

The spelling of 64381945 in words is "sixty-four million, three hundred eighty-one thousand, nine hundred forty-five".