664681480 has 64 divisors (see below), whose sum is σ = 1534224240. Its totient is φ = 259064832.

The previous prime is 664681471. The next prime is 664681489. The reversal of 664681480 is 84186466.

It is an interprime number because it is at equal distance from previous prime (664681471) and next prime (664681489).

It can be written as a sum of positive squares in 8 ways, for example, as 104980516 + 559700964 = 10246^2 + 23658^2 .

It is not an unprimeable number, because it can be changed into a prime (664681489) 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, 331842 + ... + 333838.

Almost surely, 2^664681480 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664681480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (767112120).

664681480 is an abundant number, since it is smaller than the sum of its proper divisors (869542760).

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

664681480 is a wasteful number, since it uses less digits than its factorization.

664681480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2218 (or 2214 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 43.

The square root of 664681480 is about 25781.4173388509. The cubic root of 664681480 is about 872.7124924764.

The spelling of 664681480 in words is "six hundred sixty-four million, six hundred eighty-one thousand, four hundred eighty".