664742380 has 48 divisors (see below), whose sum is σ = 1439252640. Its totient is φ = 257776128.

The previous prime is 664742369. The next prime is 664742387. The reversal of 664742380 is 83247466.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (664742387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 82282 + ... + 89998.

It is an arithmetic number, because the mean of its divisors is an integer number (29984430).

Almost surely, 2^664742380 is an apocalyptic number.

It is an amenable number.

664742380 is an abundant number, since it is smaller than the sum of its proper divisors (774510260).

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

664742380 is a wasteful number, since it uses less digits than its factorization.

664742380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7858 (or 7856 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 40.

The square root of 664742380 is about 25782.5983950416. The cubic root of 664742380 is about 872.7391451260.

It can be divided in two parts, 664 and 742380, that added together give a square (743044 = 862²).

The spelling of 664742380 in words is "six hundred sixty-four million, seven hundred forty-two thousand, three hundred eighty".