664378071 has 32 divisors (see below), whose sum is σ = 1085552640. Its totient is φ = 352774656.

The previous prime is 664378051. The next prime is 664378093. The reversal of 664378071 is 170873466.

It is not a de Polignac number, because 664378071 - 2¹¹ = 664376023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664378051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16425 + ... + 39981.

It is an arithmetic number, because the mean of its divisors is an integer number (33923520).

Almost surely, 2^664378071 is an apocalyptic number.

664378071 is a deficient number, since it is larger than the sum of its proper divisors (421174569).

664378071 is a wasteful number, since it uses less digits than its factorization.

664378071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23663.

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 664378071 is about 25775.5324096322. The cubic root of 664378071 is about 872.5796824351.

The spelling of 664378071 in words is "six hundred sixty-four million, three hundred seventy-eight thousand, seventy-one".