646645465 has 4 divisors (see below), whose sum is σ = 775974564. Its totient is φ = 517316368.

The previous prime is 646645463. The next prime is 646645499. The reversal of 646645465 is 564546646.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 564546646 = 2 ⋅282273323.

It can be written as a sum of positive squares in 2 ways, for example, as 176145984 + 470499481 = 13272^2 + 21691^2 .

It is a cyclic number.

It is not a de Polignac number, because 646645465 - 2¹ = 646645463 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646645463) 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, 64664542 + ... + 64664551.

It is an arithmetic number, because the mean of its divisors is an integer number (193993641).

Almost surely, 2^646645465 is an apocalyptic number.

It is an amenable number.

646645465 is a deficient number, since it is larger than the sum of its proper divisors (129329099).

646645465 is a wasteful number, since it uses less digits than its factorization.

646645465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 129329098.

The product of its digits is 2073600, while the sum is 46.

The square root of 646645465 is about 25429.2246244356. The cubic root of 646645465 is about 864.7463655446.

The spelling of 646645465 in words is "six hundred forty-six million, six hundred forty-five thousand, four hundred sixty-five".