64445940 has 72 divisors (see below), whose sum is σ = 210531048. Its totient is φ = 15863040.

The previous prime is 64445939. The next prime is 64445987. The reversal of 64445940 is 4954446.

64445940 is a `hidden beast` number, since 64 + 4 + 4 + 594 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 381924 + 64064016 = 618^2 + 8004^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 64445895 and 64445904.

It is a congruent number.

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, 11431 + ... + 16110.

Almost surely, 2^64445940 is an apocalyptic number.

64445940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64445940 is an abundant number, since it is smaller than the sum of its proper divisors (146085108).

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

64445940 is a wasteful number, since it uses less digits than its factorization.

64445940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27569 (or 27564 counting only the distinct ones).

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

The square root of 64445940 is about 8027.8228680010. The cubic root of 64445940 is about 400.9268921849.

The spelling of 64445940 in words is "sixty-four million, four hundred forty-five thousand, nine hundred forty".