64847640 has 128 divisors (see below), whose sum is σ = 228614400. Its totient is φ = 14507520.

The previous prime is 64847621. The next prime is 64847641. The reversal of 64847640 is 4674846.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64847641) 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 31 ways as a sum of consecutive naturals, for example, 15271 + ... + 19049.

It is an arithmetic number, because the mean of its divisors is an integer number (1786050).

Almost surely, 2^64847640 is an apocalyptic number.

64847640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64847640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114307200).

64847640 is an abundant number, since it is smaller than the sum of its proper divisors (163766760).

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

64847640 is a wasteful number, since it uses less digits than its factorization.

64847640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3817 (or 3813 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 39.

The square root of 64847640 is about 8052.8032386244. The cubic root of 64847640 is about 401.7581773748.

The spelling of 64847640 in words is "sixty-four million, eight hundred forty-seven thousand, six hundred forty".