42643664 has 40 divisors (see below), whose sum is σ = 96446208. Its totient is φ = 17884800.

The previous prime is 42643663. The next prime is 42643669. The reversal of 42643664 is 46634624.

42643664 = 320² + 321² + ... + 543².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42643661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1214 + ... + 9314.

Almost surely, 2^42643664 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 42643664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48223104).

42643664 is an abundant number, since it is smaller than the sum of its proper divisors (53802544).

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

42643664 is a wasteful number, since it uses less digits than its factorization.

42643664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8163 (or 8157 counting only the distinct ones).

The product of its digits is 82944, while the sum is 35.

The square root of 42643664 is about 6530.2116351616. The cubic root of 42643664 is about 349.3693787305.

The spelling of 42643664 in words is "forty-two million, six hundred forty-three thousand, six hundred sixty-four".