664144340 has 24 divisors (see below), whose sum is σ = 1398033672. Its totient is φ = 265023360.

The previous prime is 664144333. The next prime is 664144361. The reversal of 664144340 is 43441466.

It can be written as a sum of positive squares in 4 ways, for example, as 7862416 + 656281924 = 2804^2 + 25618^2 .

It is a junction number, because it is equal to n+sod(n) for n = 664144297 and 664144306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31019 + ... + 47858.

It is an arithmetic number, because the mean of its divisors is an integer number (58251403).

Almost surely, 2^664144340 is an apocalyptic number.

It is an amenable number.

664144340 is an abundant number, since it is smaller than the sum of its proper divisors (733889332).

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

664144340 is a wasteful number, since it uses less digits than its factorization.

664144340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79307 (or 79305 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 32.

The square root of 664144340 is about 25770.9980404330. The cubic root of 664144340 is about 872.4773446990.

The spelling of 664144340 in words is "six hundred sixty-four million, one hundred forty-four thousand, three hundred forty".