306640513 has 4 divisors (see below), whose sum is σ = 306789808. Its totient is φ = 306491220.

The previous prime is 306640507. The next prime is 306640559. The reversal of 306640513 is 315046603.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 315046603 = 1291 ⋅244033.

It is a cyclic number.

It is not a de Polignac number, because 306640513 - 2²¹ = 304543361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (306640573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71523 + ... + 75688.

It is an arithmetic number, because the mean of its divisors is an integer number (76697452).

Almost surely, 2^306640513 is an apocalyptic number.

It is an amenable number.

306640513 is a deficient number, since it is larger than the sum of its proper divisors (149295).

306640513 is a wasteful number, since it uses less digits than its factorization.

306640513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149294.

The product of its (nonzero) digits is 6480, while the sum is 28.

The square root of 306640513 is about 17511.1539596909. The cubic root of 306640513 is about 674.3362569136.

The spelling of 306640513 in words is "three hundred six million, six hundred forty thousand, five hundred thirteen".