64643487 has 4 divisors (see below), whose sum is σ = 86191320. Its totient is φ = 43095656.

The previous prime is 64643473. The next prime is 64643489. The reversal of 64643487 is 78434646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64643487 - 2¹⁰ = 64642463 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64643489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10773912 + ... + 10773917.

It is an arithmetic number, because the mean of its divisors is an integer number (21547830).

Almost surely, 2^64643487 is an apocalyptic number.

64643487 is a deficient number, since it is larger than the sum of its proper divisors (21547833).

64643487 is a wasteful number, since it uses less digits than its factorization.

64643487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21547832.

The product of its digits is 387072, while the sum is 42.

The square root of 64643487 is about 8040.1173498899. The cubic root of 64643487 is about 401.3361298399.

The spelling of 64643487 in words is "sixty-four million, six hundred forty-three thousand, four hundred eighty-seven".