645343546 has 4 divisors (see below), whose sum is σ = 968015322. Its totient is φ = 322671772.

The previous prime is 645343537. The next prime is 645343549.

It is a happy number.

645343546 is nontrivially palindromic in base 10.

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

It can be written as a sum of positive squares in only one way, i.e., 426629025 + 218714521 = 20655^2 + 14789^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 645343499 and 645343508.

It is not an unprimeable number, because it can be changed into a prime (645343549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161335885 + ... + 161335888.

Almost surely, 2^645343546 is an apocalyptic number.

645343546 is a deficient number, since it is larger than the sum of its proper divisors (322671776).

645343546 is a wasteful number, since it uses less digits than its factorization.

645343546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322671775.

The product of its digits is 518400, while the sum is 40.

The square root of 645343546 is about 25403.6128532931. The cubic root of 645343546 is about 864.1656320046.

The spelling of 645343546 in words is "six hundred forty-five million, three hundred forty-three thousand, five hundred forty-six".