664783650 has 72 divisors (see below), whose sum is σ = 1811294784. Its totient is φ = 174770400.

The previous prime is 664783649. The next prime is 664783681. The reversal of 664783650 is 56387466.

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

It is a junction number, because it is equal to n+sod(n) for n = 664783596 and 664783605.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 21547 + ... + 42353.

It is an arithmetic number, because the mean of its divisors is an integer number (25156872).

Almost surely, 2^664783650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664783650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (905647392).

664783650 is an abundant number, since it is smaller than the sum of its proper divisors (1146511134).

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

664783650 is a wasteful number, since it uses less digits than its factorization.

664783650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20896 (or 20888 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 664783650 is about 25783.3987286393. The cubic root of 664783650 is about 872.7572058566.

The spelling of 664783650 in words is "six hundred sixty-four million, seven hundred eighty-three thousand, six hundred fifty".