664437745 has 4 divisors (see below), whose sum is σ = 797325300. Its totient is φ = 531550192.

The previous prime is 664437743. The next prime is 664437791. The reversal of 664437745 is 547734466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 448465329 + 215972416 = 21177^2 + 14696^2 .

It is a cyclic number.

It is not a de Polignac number, because 664437745 - 2¹ = 664437743 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664437695 and 664437704.

It is not an unprimeable number, because it can be changed into a prime (664437743) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66443770 + ... + 66443779.

It is an arithmetic number, because the mean of its divisors is an integer number (199331325).

Almost surely, 2^664437745 is an apocalyptic number.

It is an amenable number.

664437745 is a deficient number, since it is larger than the sum of its proper divisors (132887555).

664437745 is a wasteful number, since it uses less digits than its factorization.

664437745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132887554.

The product of its digits is 1693440, while the sum is 46.

The square root of 664437745 is about 25776.6899542979. The cubic root of 664437745 is about 872.6058064968.

The spelling of 664437745 in words is "six hundred sixty-four million, four hundred thirty-seven thousand, seven hundred forty-five".