64643775 has 48 divisors (see below), whose sum is σ = 129348864. Its totient is φ = 27809280.

The previous prime is 64643743. The next prime is 64643779. The reversal of 64643775 is 57734646.

It is a happy number.

It is not a de Polignac number, because 64643775 - 2⁵ = 64643743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64643779) 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 47 ways as a sum of consecutive naturals, for example, 5304 + ... + 12546.

It is an arithmetic number, because the mean of its divisors is an integer number (2694768).

Almost surely, 2^64643775 is an apocalyptic number.

64643775 is an abundant number, since it is smaller than the sum of its proper divisors (64705089).

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

64643775 is a wasteful number, since it uses less digits than its factorization.

64643775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7280 (or 7275 counting only the distinct ones).

The product of its digits is 423360, while the sum is 42.

The square root of 64643775 is about 8040.1352600563. The cubic root of 64643775 is about 401.3367258506.

The spelling of 64643775 in words is "sixty-four million, six hundred forty-three thousand, seven hundred seventy-five".