64649880 has 128 divisors (see below), whose sum is σ = 222566400. Its totient is φ = 16675200.

The previous prime is 64649869. The next prime is 64649891. The reversal of 64649880 is 8894646.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (64649869) and next prime (64649891).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32515 + ... + 34445.

It is an arithmetic number, because the mean of its divisors is an integer number (1738800).

Almost surely, 2^64649880 is an apocalyptic number.

64649880 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 64649880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111283200).

64649880 is an abundant number, since it is smaller than the sum of its proper divisors (157916520).

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

64649880 is a wasteful number, since it uses less digits than its factorization.

64649880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1982 (or 1972 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The square root of 64649880 is about 8040.5149088849. The cubic root of 64649880 is about 401.3493596197.

The spelling of 64649880 in words is "sixty-four million, six hundred forty-nine thousand, eight hundred eighty".